Sculpt/Paint: Add Paint Studio Light preset

This studio light preset is designed for color painting tasks. As color
are multiplied on top of the current studio light/matcap, this should be
as white as possible and with very soft speculars to avoid color
distorsion while showing the volume of the mesh.

Reviewed By: jbakker, JulienKaspar

Differential Revision: https://developer.blender.org/D8209

Merge branch 'blender-v2.91-release'

Fix T81904: Cloth brush simulation failing with local area and mirror

When using local area, all nodes need to build their constraints first
before activating them for simulation. THis ensures that nodes get their
structural constraints from the initial location of each symmetry pass.

Reviewed By: sergey

Maniphest Tasks: T81904

Differential Revision: https://developer.blender.org/D9303

Sculpt: Implement plane deformation falloff for Grab

The plane deformation falloff was introduced in the first version of the
cloth brush, but due to the lack of all the new features and fixes in the
solver it was causing a lot of artifacts for deformation brushes. In
order to avoid that, the cloth brush was always using radial falloff for
the grab brush.

Now the plane falloff is properly implemented using the deformation
constraints.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D9320

Sculpt: Option to limit the action of line gestures to the segment

This adds a tool property for sculpt line gesture tools (line and
project) to limits its effect to the segment of the gesture instead of
using the infinite line to bisect the mesh in two parts.

To achieve that, the line gesture now has two extra side planes that can
be enabled/disabled for getting the nodes from the PBVH and to test the
vertices.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D9307

Sculpt: Face Set Edit delete Geometry operation

This adds an operation mode to the Face Set Edit tool which deletes the
geometry of a Face Set by clicking on it.
The operator also checks for the mesh having a single Face Set to avoid
deleting the entire object by accident.
This is also disabled for Multires to avoid modifying the limit surface
without control (it is not an important limitation as base meshes for
multires are usually final, but maybe it can be supported in the future).

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D8938

Sculpt: Grab silhouette option

This adds a property to the grab that masks vertices based on its
original normal and grab delta. When used on thin meshes, it allows to
grab the silhouette from one side of the object without affecting the
shape of the other side.

Reviewed By: sergey

Differential Revision: https://developer.blender.org/D9205

Fix T81932: Dyntopo crashing with sculpt vertex colors brush tools

Paint and smear tools are only implemented for regular mesh PBVH,
meaning they are not supported by the dynamic topology and multires
sculpting.

These tools are to be ignored for an unsupported sculpt modes, regardless
of state of user preferences.

Reviewed By: sergey

Maniphest Tasks: T81932

Differential Revision: https://developer.blender.org/D9308

Merge branch 'blender-v2.91-release'

Sculpt: Remove tools with missing icons experimental option

All tools planned for 2.91 now have icons, so this option can be
removed.

Reviewed By: dfelinto, Severin

Differential Revision: https://developer.blender.org/D9299