[BUGFIX] Always quote SQL identifiers in schema migrations

Doctrine doesn't always return quoted identifiers when reading the
schema information from the database. This patch works around that
by properly quoting the identifiers when determining the required
changes to the database.

Resolves: #81610
Releases: master, 8.7
Change-Id: I746a8a023cf494050cd83c089e0d2bca98c046f1
Reviewed-on: https://review.typo3.org/53373


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>