[BUGFIX] Prevent malformed SQL query in AbstractDatabaseRecordList

This change prevents the creation of a malformed SQL query in
AbstractDatabaseRecordList::makeQueryArray. The problem was
caused by the makeSearchString method returning `1=1` from two
early decisions, whereas before it would return a valid query
prepended with AND but containing no search clauses.

Returning an empty string from these two early decisions will
completely solve the issue without breaking the search feature
that uses this function.

Change-Id: Ic9b48bc498a7423d158057fbcee05f976ee1dadf
Resolves: #78353
Releases: master
Reviewed-on: https://review.typo3.org/50284


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>