vegas: update and refactor maschine3 screen redraw
vegas: update and refactor maschine3 screen redraw

Now using the callback style APIs, allowing Ctlra to control
when the screens are redrawn, and to handle and allocate memory
more efficiently etc.

Signed-off-by: Harry van Haaren <6e1296516ee88185cd60d9725251227ece1af74d@gmail.com>

openAVproductions/openAV-Ctlra