add new files
fix pipeline requirements

 : Reviewed migration, play_onchanges usage, and unit tests

in case other modules also install companies.

This would happen when running tests on a DB where ``account_period`` is
already installed.

Follow-up on rev 7bde6eae1dcf.

Upgraded the module version.
Updated the change log.

based on menu items.

Also update tests in this module to use them instead of creating them anew.

To be reworked.

or an accounting document.
Updated the translations.

Specifics to play better with accounting changes:

* No longer change the base ``date`` field; add ``accounting_date`` instead.
* Build periods when loading accounting data for a new company.