[FIX] core: avoid losing translations during module upgrade

Consider field F in module X with parameter translate=False, and F is
overridden in module Y with parameter translate=True.  During the
upgrade of module X, module Y hasn't been loaded yet, and the ORM
considers the field to be `translate=False`.  Therefore it converts its
database column from type jsonb to varchar, and accidentally drops
non-en_US values:

    {"en_US": "English value", "fr_FR": "French value"} (jsonb)
        -> 'English value' (varchar)

As a result, translations are lost after upgrade.

This commit fixes the bug by checking whether the field is translated in
database and patches the field accordingly when loading the registry.
This avoids the ORM considering the field as non-translated while
upgrading modules.

In order to "force" translated fields to become non-translated ones, at
the end of the loading process the patch above is discarded, and fields
are checked again.  We then adapt the schema of models that have such
fields.  This extra step handles the uninstallation of modules like
module Y in the example above.

The patching of the fields has one potential issue.  While upgrading
module X, field F is patched with translate=True.  If module Y actually
overrides F with translate=xml_translate or so, this may cause the
behavior of the upgrade to be slightly incorrect.  Because of the
complexity, we have chosen to not support this case.

closes odoo/odoo#110572

Signed-off-by: Raphael Collet <rco@odoo.com>
Co-authored-by: Raphael Collet <rco@odoo.com>