[FEATURE] Auto DB fields from TCA for type "flex"

Tables with TCA columns set to type="flex" do not
need an ext_tables.sql entry anymore. The core now
creates this field automatically.

This is one of many patches in this area: The v13 goal
is to obsolete ext_tables.sql in most cases by
creating default "business" fields of TCA tables
automatically.

The patch adds the main magic in class DefaultTcaSchema
and removes own ext_tables.sql definitions having
type=flex.

Resolves: #101997
Related: #101553
Releases: main
Change-Id: Ide5458994cfbfca0113be08b0e87b51babaeb540
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/81158


Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>