Add panels with overlay settings for strips and preview and overlay
enable/disable button.
Entries from the View menus moved to the overlay panels, which will
simplify cluttered View menus.
Additional options have been added:
- Strip Name
- Strip Source(ex. path)
- Strip Duration
So users can now select what info they need to see on the strips. When
No text is displayed, waveforms are drawn in full height.
Reviewed By: ISS, HooglyBoogly, pablovazquez
Differential Revision: https://developer.blender.org/D9751