last constraints, checks, defaults, and indices for database columns were added

Database Review

Are all constraints, checks, default values, and indices for database columns installed properly?
Did we have other default values in the old database?
Can we propose default values for every column, so we do not have to define nullable columns within the database (slow access to those)?

Check all of these constraints and check, whether sqlacodegen still generates the same classes as coded in this repository.

Also check on "ON DELETE CASCADE" table attributes. Notes regarding this issue can be found in comment https://gitlab.version.fz-juelich.de/esde/toar-data/toardb_fastapi/-/issues/7#note_82561.

Changes to the database (including on delete cascade): see comment https://gitlab.version.fz-juelich.de/esde/toar-data/toardb_fastapi/-/issues/7#note_86643