Changed object selection to be done on press instead of click, and
the initial press now also starts free drag of the selected object
after a short distance moved to prevent accidental drags.
Change-Id: I61656661cd734d167ef9f8db42d986f0e97402a3
Fixes: QDS-2376
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>