Blender Git Loki

Cleanup: move check_drag & check_click out of wmEvent

These variables track the wmWindow.event_queue state,
however they were used in a way that wasn't correct.

- check_drag & check_click from wmWindow.eventstate
were used to track the click/drag status of events handled in
wmWindow.event_queue.
- Event's in the queue read from wmEvent.check_drag.
- Once a drag action was detected, wmWindow.eventstate.check_drag
was disabled.

Disabling drag in the event state would not change the drag state
for values already in the event queue.

Simplify logic by moving these values into the window,
so there is one place these variables are tracked.