QtIFW

Fix arguments in RegisterFileType

When using RegisterFileType, argumens include progId.
Removed it from arguments and saved as member variable.
This way progId won't interfere argument check count and
it can be used also in undo operation.

Change-Id: Ic80a54a28b5e171a5d4e3023b58eb1636a16fa49
Reviewed-by: Karsten Heimrich <karsten.heimrich@theqtcompany.com>