Blender Git Loki

Fix T68723: GPencil - Split Select mode for Sculpt and Edit mode

Actually, the selection mode is not visible in Sculpt mode when mask is enabled, but still is used.
Also, the mode is shared between Edit mode and Sculpt mode and for meshes the selector is by mode.

This commit splits the select mode in different properties and show the selector in Sculpt mode to define the Select mode. Also, the Select Mask button has been removed and now the Select Mode buttons work equal to Meshes where the select buttons are the mask enable too.

Fixed some old code not valid detected during these changes.

Differential Revision: https://developer.blender.org/D5500