build: Use Qt top-level build facilities
build, qt: Add linguist_tools list
build, qt: Drop lrelease dependency patch
It is no longer required after switching to Qt top-level build.
build, qt: Drop translations.pro hack
It is no longer required after switching to Qt top-level build.
build, qt: Force bootstrap while building linguist tools
Qt lrelease tool depends on the xml module. This change guarantees that
it is always available after being bootstrapped.
build, qt: Fix wrong cross-compiling detection on macOS
This is a backport of core#20641