Allow to manually specify QT moc path for custom QT distributions

[Jeordanis]

Is your feature request related to a problem? Please describe.

This is needed to be able to use the moc compiler when linking to custom distributions of QT with a specific directory structure.

Describe the solution you'd like

Something similar to what we have in cmake where we can set the variable “ AUTOMOC_EXECUTABLE” to the path of the moc executable and then enable “AUTOMOC”.

Describe alternatives you've considered

No response

Additional context

No response

[waruqi]

no way now, you can put moc to qt/bin or qt/libexec directory.