More sculpt mask tools: Smooth & draw

The idea would be to have more tools to paint sculpting masks, such as: -Smooth: Smooths the sculpt mask only, useful for fading details on an area. -Draw: Has a "weight" input on top of it's strength, so you can use it to "overwrite" areas with weights different than 1 or 0 easily, so if you want to have a 50% mask over a large area it's much easier than having to do it with a 50% strength brush which would just overlap itself and not work at all