Odoo appliance needs to be updated to support standard deployment pattern

[a3s7p]

From #511 (comment):

Would it be possible to not have Odoo Package install into /etc/python3
It would be very nice if Odoo code were more accessible.
Also would be nice if there were some ways to "personalize" (ie Git Clone etc) the Odoo code base in a TKL container.

I'm not sure if actual Odoo source code needs to be changed as it is fairly barebones and does not do much by itself. Upstream seems to assume any code changes will happen in the addons. However the Odoo-supplied containers offer a way to mount extra addons in the container which should solve this as everything from the base modules can be inherited/overridden in the addons.

Related, have an issue where TKLBam migrating from 16.x to 17.x TKL Odoo, some of the data sets change and the restoration does not work. Would be best there, to have a way to move the 17.x Odoo code base into 16.x, run Database -U command (verify that that works in fact), then run a backup on 16.x system. Open 17.x system and run a restore.

This will probably require updating the tklbam profile and trying to detect if there is a version change / migration, cloning the neutralized live database, migrating the neutralized database and proceeding with the live database if that worked... so fairly complex but if we can make it rollback at any failure and not lose data it would be good to have.

The idea for the "new" Odoo appliance is to use upstream-supplied Odoo containers as those are probably the easiest and most reliable way to deploy. It also has to provide a way to run Odoo Enterprise easily as the additional Enterprise modules are shipped in a separate package. This can be solved by mounting the extra addons to the container.