At the moment only the Qt internal qt_manual_moc function allows
manually running moc and generating a metatypes json file.
There is no such functionality available in the public qt6_wrap_cpp
and qt6_generate_moc functions.
Change qt6_wrap_cpp to accept a new internal option called
__QT_INTERNAL_OUTPUT_MOC_JSON_FILES to allow creating and retrieving
the associated json file with metatypes information.
This is needed to fix qtremoteobjects CMake API which needs to run moc
manually and process the metatypes json file.
The option is internal because we don't want to introduce new API in
6.2.0.
Task-number: QTBUG-95832
Change-Id: Ic8dd27fc960c3f8dea8c101dfc028db45494953d
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Jani Heikkinen <jani.heikkinen@qt.io>
(cherry picked from commit 90e7d6db1bb44de3629ec2b70df26fbafe4294fa)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
f4aaba593c