Enable Masking Feature to Edit & Object mode and add python api of that.

Pablo Dobarro created an awesome mask brush for sculpting mode. But, that mask brush should be available to other modes as well. By enabling masking feature to edit mode and object mode would open the door for creativity with freedom. Example: creating terrain with more control over it. like, with one same plane we can create a canyon-like terrain on the specific part of the plane and one the other hand we can create other types of terrains on that plane. we will achieve that by masking some specific part of that plane. and we can create some detailed work on that terrain by making and messing around with it. and if we create the python API to know the masked part of the geometry with specific id allocated to that masked part of the geometry. we can build an awesome python script or add-on for terrain building that currently available scripts or addon lake of. of course, there are many ways to use the masking feature. but, at time of writing this, I've only terrain building idea. I think it's an easy task. because masking feature is already available in sculpt mode.