cmake: fix variable names in FindRagelForTrojita

Thanks to Pali for reporting this.

REVIEW: 112768
cmake: fix variable names for Find{,Qt5}LinguistForTrojita

The cmake's conventions say that FindXXX shall work with XXX_FOUND and
XXX_FIND_QUIETLY, so let's stop being creative here.

Thanks to Pali for reporting this.

REVIEW: 112769