[EXPERIMENTAL] Context menu events test
Because in the Linux context menu calling on mousePress, the mouseRelease
event is not executed. This making a bugs on mousePress to scene while
menu is opened.
This test applied only to the blocks. Other item types will be implemented
after done debug of this test. This must fix the old bug with mouse events.
With this test, the block's context menu will be opened after mouseRelease
event on the Linux.

Be careful, with this test you will get a bugs with context menu with other
items like BGO, NPC, door points, physical environment zones.