[PATCH] qt: Consolidate to one toOUString helper

[PATCH] qt: Consolidate to one toOUString helper

Instead of having one for vcl in vcl/inc/qt5/QtTools.hxx
and one in avmedia/source/qt6/QtFrameGrabber.cxx,
move the existing implementation to
include/vcl/qt/QtUtils.hxx and use it everywhere.

Change-Id: I8576ab0fe2fd12bb25ae262e59acb8412ef8be0c
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/184057
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
(cherry picked from commit d023035acf83ee1b61dfc03333bfc6e612bb58f6)

Gbp-Pq: Name qt-Consolidate-to-one-toOUString-helper.diff