This commit improves the user flow for account returns.
When selecting a return, the chatter no longer opens in a side panel.
Instead, a new view is shown displaying:
 - The return card (with stages and buttons),
 - The related checks (as a kanban view),
 - And the chatter on the side.

This unified view offers better clarity and usability. Since the checks
are shown in a kanban view, users can benefit from filters and search
functionality on them.

Additionally, a new stage "Lock" has been added between "Review" and
"Submit" in the VAT return flow. This clarifies to the user that the
return period will be locked before submission. This new stage
generates the closing move and files (xml, pdf, ...) which can then
be used in the submission stage.
For Belgian localization (l10n_be_reports), this change implies that
prorata and potential restitution parameters are now requested at the
"Lock" stage, as they're essential for generating the XML file.

The return checks also see significant changes. They no longer use a
dedicated form view or an associated chatter. The approval process
of a check is now more robust. Both Bookkeepers and Accountants can
validate a check. If a Bookkeeper approves a check, an Accountant
can subsequently "supervise" it. Once supervised by an Accountant,
that specific check can no longer be invalidated by a Bookkeeper.

Finally, Bookkeepers can no longer reset a tax return.

task-4891073

Community PR: https://github.com/odoo/odoo/pull/218871

This PR adds a third connection type to the IoT box, using the WebRTC protocol. This commit handles the browser side of the connection.

The WebRTC connection is added as a third connection type to the existing `iot_http` service, with the highest priority. The first time it is used, the connection will not be open yet so it will fail, but will begin establishing the connection in the background. The next time an IoT message is sent, it can use the WebRTC connection.

We use the Browser APIs `RTCPeerConnection` and `RTCDataChannel` to setup the WebRTC connection to the IoT box. The flow is as follows:

1. Browser creates an `RTCPeerConnection` instance, generates an 'offer' and sends it to the IoT box via the existing WebSocket connection.
2. The IoT box receives this offer, and sends us back an 'answer', again via the WebSocket connection.
3. At this point the browser will automatically establish the connection to the IoT box. Any future calls to `iot_http` will use this connection (unless it fails, in which case it will fallback to the other connection types as before).

This implementation is intentionally very simple.
This means we do not use a STUN server, and so the connection will only work on the local network. This isn't a huge problem because in the case you are not on the same network as the IoT box, the WebSocket connection will still work and there would be little gain from using WebRTC.

task-4894918

Description of the issue/feature this PR addresses:
The current contact UI is partly inconsistent regarding the child/parent behavior and also it is not flexible extensible regarding new contact types like "Home office Contact", which is a "Contact" but has a different Address, and also an "Delivery Address" is in my opinion not an individual, but neigther a company. 

Therefore I suggest to de-couple the different topics and add new variables. These variables can be customized by overwriting the 
"_compute_contact_type" method according to the users needs.

e.g. you could add a new individual type "home office contact" which is an individual, but also has an editable address.
By changing can_be_child to True on Company contacts, you could create multi-level company structures.

In this patch, the current behavior is not changed, but gives better possibilities for customizations.

Current behavior before PR:
The forms are hardly customizable regarding new contact types.

Desired behavior after PR is merged:

The UI can be more customizable and using is_address_readonly, is_individual, can_be_parent and can_be_child instead of linking the type directly.


---
I confirm I have signed the CLA and read the PR guidelines at www.odoo.com/submit-pr