[16.0][FIX] account_invoice_margin_sale: Post-install test + fallback to load CoA

[victoralmau]

Since odoo/odoo@d0342c8, the default existing company is not getting a CoA automatically, provoking than the current tests fail with the error:

odoo.exceptions.UserError: No journal could be found in company My Company (San Francisco) for any of those types: sale

Thus, we put tests post-install for being sure localization modules are installed, the same as AccountTestInvoicingCommon does, but we don't inherit from it, as it creates an overhead creating 2 new companies and loading their CoA and some more stuff, while we don't need all of that.

Besides, if you don't have l10n_generic_coa installed, you can't use another CoA (like l10n_es) easily, so we put little code to select the first available CoA.

@Tecnativa

[OCA-git-bot]

Hi @carlosdauden, @sergio-teruel, some modules you are maintaining are being modified, check this out!

[victoralmau]

Ping @pedrobaeza

[github-actions[bot]]

There hasn't been any activity on this pull request in the past 4 months, so it has been marked as stale and it will be closed automatically if no further activity occurs in the next 30 days. If you want this PR to never become stale, please ask a PSC member to apply the "no stale" label.

[OCA-git-bot]

This PR looks fantastic, let's merge it! Prepared branch 16.0-ocabot-merge-pr-242-by-pedrobaeza-bump-patch, awaiting test results.

[OCA-git-bot]

Congratulations, your PR was merged at ec857033e10ef45c92d757053278adab425dec68. Thanks a lot for contributing to OCA. ❤️