[BUGFIX] Prevent statements with COUNT() and ORDER BY parts for PostgreSQL

In PostgreSQL it's not allowed to use a COUNT statement with an ORDER BY
statement as long as the field for sorting not available in GROUP BY
clause. Therefor we have to parse the SQL and drop ORDER BY clause for
selections with a count.

Resolves: #43262
Releases: master
Change-Id: I30cedfa2c25a5b2a8c6f7cb56c2dd2bc28e185ec
Reviewed-on: http://review.typo3.org/21091


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>