- add version switch for backend fsp test

(cherry picked from commit 67b22cee3ab2c17b61100f1ccd69081082c0f074)

an issue with just one test

of the :class:`.mysql.DATETIME`, :class:`.mysql.TIMESTAMP` and
:class:`.mysql.TIME` types would be incorrectly placed into the
``timestamp`` attribute, which is unused by MySQL, instead of the
``fsp`` attribute.
fixes #3602

individual categories w/ modernized fixtures, assert attributes
within type objects.

primary key before emitting an INSERT, and merges distinct objects with
duplicate primary keys together as they are encountered, which is
essentially semi-deterministic at best.   This behavior
matches what happens already with persistent objects.
fixes #3601

fail to emit an UPDATE in the case where the attribute were set to
None and not previously loaded.
fixes #3599

such as a CHECK constraint would render an erroneous comma in the
definition; this scenario can occur such as with a Postgresql
INHERITS table that has no columns of its own.
fixes #3598