### Steps to Reproduce:
1) Install `website_helpdesk_slides_forum` module
2) On a Helpdesk team, link 2 (or more) forums under `Commnity Forums`.
3) Click on website smart button and then click `Ask the community` button.

### Error:
```
odoo.addons.base.models.ir_qweb.QWebException: Error while render the template
KeyError: '_forums'
Template: website_helpdesk_slides_forum.helpdesk_forums
```

### Root Cause:
https://github.com/odoo/enterprise/blob/1bdd673c5fd19e335dc0948d2beed7a282e5e172/website_helpdesk_forum/controllers/website_forum.py#L18-L22

On clicking the "Ask the Community" button calls the `helpdesk_forums`
controller. A single forum redirects straight to it. Several forums get rendered
through `get_template_xml_id()`, with only `forums` in context.

`get_template_xml_id()` is overridden in `WebsiteSlidesForumHelpdesk`,
which points to :

https://github.com/odoo/enterprise/blob/1bdd673c5fd19e335dc0948d2beed7a282e5e172/website_helpdesk_slides_forum/views/helpdesk_templates.xml#L3-L5

a primary copy of the inner partial `forum_all_all_entries`. That
partial needs `_forums` (and, once extended by website_slides_forum,
courses_discussions too), both only ever set by the page template's
own t-call:

[Reference](https://github.com/odoo/odoo/blob/23af2b443735c6d3a2f64e44f9ea5da45638b052/addons/website_forum/views/forum_forum_templates_forum_all.xml#L18-L19)

Since `helpdesk_forums` is rendered directly instead of going through
`website_forum.forum_all`, `_forums` is never set, hence
`KeyError` occurs.

The base `website_helpdesk_forum` module has the same root cause one
level up, surfacing as a different error:

https://github.com/odoo/enterprise/blob/1bdd673c5fd19e335dc0948d2beed7a282e5e172/website_helpdesk_forum/controllers/website_forum.py#L24-L25

`website_helpdesk_forum.forum_all` does not exist anywhere in the
codebase. A team with multiple forums, without
`website_helpdesk_slides_forum` installed, hits
```
ValueError: View 'website_helpdesk_forum.forum_all' in website 1 not found
```
Instead of a listing page.

### Fix:
- Both `get_template_xml_id()` implementations now return the real,
  working `website_forum.forum_all` page template, which already sets
  `_forums/courses_discussions` through its own `t-call` and wraps the result in
  website.layout.

- `helpdesk_forums()`'s render values are now built through an overridable
  `_get_helpdesk_forums_render_values()` hook instead of a hardcoded dict,
  so subclasses can extend the context.

- `website_helpdesk_slides_forum` uses that hook to set
  `hide_forum_slides_link=True`, and adds one small non-primary view inheriting
  `website_slides_forum.forum_all_all_entries` that conditions the `/slides` promo
  link (not the "Course" badge, which doesn't navigate anywhere) on `not`
  `hide_forum_slides_link`. This targets the link element itself rather than a
  `t-call` site in `forum_all`, so it correctly applies whether `website_slides_forum`
  groups a given forum as "regular" or "course-linked".

**opw-6332175**

Account reports can use "Load More" to paginate the lines generated when expanding a groupby. A report line can contain several expressions, which may return overlapping grouping keys.

Problem:
The limit and offset are applied while computing each expression, before their results are aggregated by grouping key. As a result, a grouping key from a previous page can be returned again by the next "Load More" request.

This results in duplicate report lines.

In 17.0, this causes an Owl error because `line.id` is used as the key when rendering the lines, and the lines can’t be viewed.

The DIOT report is affected because it contains multiple expressions whose grouping keys can overlap.

Solution:
Disable "Load More" on the DIOT report by removing its pagination limit.

Example steps to reproduce:
1. Create or switch to a Mexican company and install `l10n_mx_reports` so the DIOT report is available.
2. Create a partner and 100 posted journal entries for that partner in the same period. Add the `+DIOT: 16%` tag to all 100 account move lines and the `-DIOT: Retención` tag to the first 90.
3. Open Accounting > Reporting > Tax Reports > DIOT.
4. Unfold the partner and click "Load More".

Related ticket:
opw-6471063

*=account,stock,test_resource

**PROBLEM**
float_round method introduces a small error in the result because of normalization/denormalization.
For example, `float_round(4.44444, precision_rounding=0.03)` returns
`4.4399999999999995` instead of the closer IEEE 754 binary 64 value of `4.4400000000000003908` (that would be printed as `4.44`).
Most of the time this is ok, but in some very very particular cases, this rounding error can affect the result of further computations.
Below are steps for a legitimate use case where this fails.

**STEP TO REPRODUCE**
1. Install l10n_be, and use the be demo company.
2. Create a 21% tax, price included. Create a fixed tax of 0.01, affecting basis, but not price included.
3. Create two lines:
- qty = 3, unit price = 8.95, discount = 30%, the 21% tax price included.
- qty = 1, unit_price = 80.20, discount = 40%, fixed tax then 21% tax price included.
4. Validate the invoice, the `subtotal_amount` and the `total_amount` of the first line will be wrong (a surplus of one cent).
5. If you generate a ubl file to send to peppol, and you try validating it, this surplus of one cent will cause peppol to refuse the invoice.

**CAUSE**
When entering _compute_all_tax() the first time the unit price for the first line is `8.95` (or at least the closest float representation of `8.95`).
compute_all() returns the right result this time.
We enter it a 2nd time, but this time, the orm have rounded the unit price using `float_round()`, introducing a small error (unit price is `8.950000000001`).
compute_all() returns a result that is wrong because of the small error in unit price, it's this wrong result that is used on the invoice.

opw-6227836

TL;DR
When downloading a `.zplii` shipping label from the chatter on a Delivery Order
(using FedEx), the browser automatically adds .txt to the end of the filename,
saving it as `.zplii.txt`

Step to reproduce:
- install `delivery_fedex_rest` with demo
- open shipping method menu -> Fedex Us -> label format = `zplii` -> save
- create a SO, click on 'Add Shipping", 
- select fedex as shipping method -> get rate -> add -> confirm SO
- go to delivery and validate
- notice, in thread, a attachment with ZPLII extension appears
- download (.txt is appended to file)

Issue:
- `fedex_rest_send_shipping` post message with documents with extension as 
`fedex_rest_label_file_type` i.e. `ZPLII`
https://github.com/odoo/enterprise/blob/735490d7ba9bdc6d0df7a0bd07c0d4e36d1ed2d4/delivery_fedex_rest/models/delivery_fedex.py#L193-L195
- when the attachment is created for this document , it's mimetype is computed
to be `text/plain` from [guess_mimetype](https://github.com/odoo/odoo/blob/5de4a5f6caee09881e7e147062f9eab9f8916a61/odoo/tools/mimetypes.py#L192) method, as data is plain ASCII code
- moreover, when downloading, [_get_stream_from](https://github.com/odoo/odoo/blob/5de4a5f6caee09881e7e147062f9eab9f8916a61/odoo/addons/base/models/ir_binary.py#L89) tries to guess extension
using [get_extension](https://github.com/odoo/odoo/blob/5de4a5f6caee09881e7e147062f9eab9f8916a61/odoo/tools/mimetypes.py#L210) which return `None` as len('zplii') > 4, [see](https://github.com/odoo/odoo/blob/5de4a5f6caee09881e7e147062f9eab9f8916a61/odoo/tools/mimetypes.py#L221)
- finally, as we got `None`, and mimetype is `text/plain`, `.txt` is appended [here](https://github.com/odoo/odoo/blob/5de4a5f6caee09881e7e147062f9eab9f8916a61/odoo/addons/base/models/ir_binary.py#L149)

Fix:
- we use `zpl` as extension for file instead of `zplii` as there is not 
difference between them from printing perspective
- as length of 'zpl' is <=4 , `get_extension` will considered it as valid

opw-6410968