[ENHANCEMENT] Allow mask keyboard shortcuts to be context sensitive.
Right now they only ever operate on the layer mask.
If the currently selected panel is an effect that has mask(s) then I believe the mask shortcuts should operate the effect masks.
After all if we are working on an effect (selected panel) and it has masks, at that moment we are concerned and interested in that mask and not a layer mask if present. Right now we have to resort to using the drop down menu.