ki18n: Include legacy catalogs defenitions in KLocalizedString
KLocale: Make sure KLocalizedString has an application catalog before using KLocale::global()
ki18n/KLocale: Re-enable useTranscript kconfig option lost in the ki18n move
ki18n: Move ki18n classes back to kdecore
ki18n: Fix CMakeLists.txt files after moving ki18n back to kdecore
ki18n: Use kdecore_export.h rather than non-existing ki18n_export.h
Move KLocalizedString language list back to KLocale