Blender Git Loki

Fix T87041: Driver Editor not updated in realtime

Caused by {rBbbb2e0614fc3}

Since above commit only the playhead is updated as an overlay in
animation playback (was moved out of drawing of the main region for
perfomance reasons).
The driver value "debug" visualization is very useful to have during
playback though but was left in main region drawing as part of
`draw_fcurve` (thus does not update in realtime anymore).

Moving `graph_draw_driver_debug` into the overlay is not feasible
because it requires animation filtering which has significant overhead
which needs to be avoided in the overlay which is redrawn on every UI
interaction.

Now tag the whole main region for updates in the Driver Editor during
playback instead (which will make the Drivers Editor as slow during
playback as before rBbbb2e0614fc3 -- but with realtime updates of the
debug visualization).

Maniphest Tasks: T87041

Differential Revision: https://developer.blender.org/D12003