Counting the results of the ``QueryResultInterface`` proxy returned by
Repository finder methods always executed a ``COUNT query`` even if
the results had been fetched or counted already.

With this patch the number of results is cached as soon as the result
is initialized and/or counted once.

Resolves: #67837
Releases: master, 6.2
Change-Id: I98f680372b845f992ad3d436647b0cf5e460b606
Reviewed-on: http://review.typo3.org/40750


Reviewed-by: Stephan Großberndt <stephan@grossberndt.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>