Sculpt: slight topology rake performance inprovement.

Produces almost the same result but takes in account all the edges instead
of only four, which gets rid of the need to select specific edges. Also,
added a check to prevent it from destroying boundaries.

Differential Revision: https://developer.blender.org/D5763

Sculpt: add Topology Rake, to align edges along brush while painting.

This helps to generate cleaner topology and define sharp features for dynamic
topology. Best used on relatively low-poly meshes, it is not needed as much
for high detail areas and has a performance impact.

Differential Revision: https://developer.blender.org/D4189