Blender Git Loki

Fix #19638: crash when assiging self in boolean modifier.

Also:
* UI now takes ID self check flag into account so that e.g. it
doesn't offer to the make object it's own parent.
* Mesh loop cuts number of cuts had wrong limits.
* Don't use mesh_get_derived_final in modifier stack, but
ob->derivedFinal instead. Avoids crashes on dependency loops,
and in case there is no loop it should have been created.