Currently, an error occurs when a user sends a customer statement.

**Steps to Reproduce ([Video](https://drive.google.com/file/d/1soOylzCVnNCNsWUBizeBQ9vfFlI5pzSP/view)):**
 - Install the `account_reports` module.
 - Go to `Invoicing` > `Customers` > `Customers`.
 - Switch to `List view`, select `a customer`, then click on `Actions` > `Open Customer Statements`.
 - Click `Send`, remove the `Email Template`, add a `subject`, and then click `Print & Send`.

**Error:**
`ValueError: Expected singleton: mail.template()`

After [this commit], which checks whether the template has an email_from, when a user sends the customer statement and removes the email template, it still tries to access the template to fetch email_from for a particular customer [1]. If no email template is used, this results in an error [2] when going to extract the email_from.

This commit ensures that email_from is taken from the email template if one is used; otherwise, it uses the current user's email address [3], which matches the default behavior.

[this commit]: https://github.com/odoo/enterprise/commit/22c46e4f63e7b2dc0eee16fc807656cd4de21fb7

[1]- https://github.com/odoo/enterprise/blob/dc4d5633407ccc728d30de5ce2072a80c16b2766/account_reports/wizard/account_report_send.py#L246

[2]: https://github.com/odoo/odoo/blob/0dabb221225fba96c0e55779afadd9f12b369777/addons/mail/models/mail_render_mixin.py#L691-L693

[3]: https://github.com/odoo/odoo/blob/0dabb221225fba96c0e55779afadd9f12b369777/addons/mail/models/mail_thread.py#L2891-L2892

sentry-7106576491

Forward-Port-Of: odoo/enterprise#102682
Forward-Port-Of: odoo/enterprise#102219

Steps to reproduce:
-------------------------
- Upgrade from lower version to 19.0 or higher.
- Start a fiskaly registered company's session.
- Close the session after transactions.

Issue:
-------
- Tax mapping used to send data to fiskaly is not set.
- If have `-` in company name or cash move reason and try to do cash move will give a tb.

Cause:
---------
- When the user's database is upgraded, the taxes already exist and the company is already registered. As a result, `l10n_de_vat_export_data` is never set, and since no tax changes occur, `l10n_de_vat_definition_export_identifier` is also not generated. This leads to incorrect values being sent to Fiskaly during the session closing request, causing errors.
- The cash statement name uses - as a separator, the current structure is `{session_name}-{move_type}-{statement_type}-{move_reason}` set from `_prepare_account_bank_statement_line_vals()` If move_reason or company name contains additional `-` splitting the whole name breaks the expected structure.

Fix:
-----
- We have added a check to identify any taxes that are missing their tax mapping If such taxes are found, we filter them and trigger the logic to set their mappings. However, if the main mapping reference value l10n_de_vat_export_data is not set, we first retrieve and update it. Once this reference is available, we update all taxes that were previously unset and then prepare the correct tax data.
As a result, the first session closing after the upgrade will automatically correct all issues both for customers who have already upgraded and for those who upgrade in the future.
- We first remove the `{session_name}-` prefix, then split the rest. Since move_type and statement_type never contain -, we take them directly not user inputs, and then rejoin everything from index 2 onward to reconstruct the correct move_reason.

Additional fixes:
--------------------
- Some places the limit of characters may exceed than what fiskaly is asking than it can give us an error so restricted all places where needed.
- We don't have check if the settlement is present if not getting id directly may cause error.

help ticket: 5362897, 5367425

Forward-Port-Of: odoo/enterprise#102855
Forward-Port-Of: odoo/enterprise#101468

Currently, an error occurs when clicking the `Send to eTIMS` button on vendor bills.

Steps to Reproduce:
 - Install `l10n_ke_edi_oscu` module without demo data.
 - Create a New company with `Kenya` as the Country and switch to it.
 - Go to Vendors > Bills, create a new bill, and add an invoice line without tax.
 - Confirm it, then click `Send to eTIMS`.

Traceback:
```py
 File "/home/odoo/src/enterprise/19.0/l10n_ke_edi_oscu/models/account_move.py", line 551, in action_l10n_ke_oscu_confirm_vendor_bill
    content = move._l10n_ke_oscu_json_from_move()
  File "/home/odoo/src/enterprise/19.0/l10n_ke_edi_oscu/models/account_move.py", line 199, in _l10n_ke_oscu_json_from_move
    line_items = self._l10n_ke_oscu_get_json_from_lines(tax_details)
  File "/home/odoo/src/enterprise/19.0/l10n_ke_edi_oscu/models/account_move.py", line 250, in _l10n_ke_oscu_get_json_from_lines
    tax, line_tax_details = next(
StopIteration: null
```

This error occurs because when a new company is created, the `eTIMS Server Mode` in Settings is empty. As a result, `l10n_ke_oscu_is_active` field becomes `False`, and at [1] the `l10n_ke_validation_message` field will also be `False`, causing the flow to be skipped. Therefore, no error is raised on the frontend side. The field `l10n_ke_oscu_is_active` is set to `True` only when `eTIMS Server Mode` is set to `Demo`.

Here we raise a warning when the `eTIMS` configuration is not set up correctly.

[1]: https://github.com/odoo/enterprise/blob/7fb7b3168039f00b6d815202bc19ac35aa1d9b5e/l10n_ke_edi_oscu/models/account_move.py#L91-L93

sentry-7083978544

Forward-Port-Of: odoo/enterprise#101319