[BUGFIX] Detect TEXT/BLOB changes in schema analyzer

Length changes of TEXT/BLOB type are not analyzed by the Doctrine
schema analyzer as only MySQL has different length version of these
fields. Add a custom column comparator that compares the different
fields length on MySQL to properly detect changes in field type.

Resolves: #79722
Releases: master
Change-Id: I2e448dcde02c3fa370496b4920dfad536fbafcd6
Reviewed-on: https://review.typo3.org/51807


Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>