Merge branch 'blender-v2.92-release'

Fix typo in UI message.

Noted by Satoshi Yamasaki (@yamyam) in rBTS5522.

Merge branch 'blender-v2.92-release'

Refactor modifier copying code.

Things like pointers to particle systems, or softbody data being stored
outside of its modifier, make it impossible for internal modifier copy
data code to be self-contained currently. It requires extra processing.

In existing code this was handled in several different places, in
several ways, and alltogether fairly inconsistently. Some cases were
even not properly handled, causing e.g. crashes as in T82945.

This commit addresses those issues by:
* Adding comments about the hackish/unsafe parts `psys` implies when
copying some modifier data (since we need to ensure particle system
copying and remapping of those pointers separately).
* Adding as-best-as-possible handling of those cases to
`BKE_object_copy_modifier` (note that it remains fragile, but is
expected to behave 'good enough' in any practical usecase).
* Remove special handling for specific editor code
(`copy_or_reuse_particle_system`). This should never have been
accepted in ED code area, and is now handled by
`BKE_object_copy_modifier`.
* Factorize copying of the whole modifier stack into new
`BKE_object_modifier_stack_copy`, now used by both `object_copy_data`
and `BKE_object_link_modifiers`.

Note that this implies that `BKE_object_copy_modifier` and
`BKE_object_copy_gpencil_modifier` are now to be used exclusively to
copy single modifiers. Full modifier stack copy should always use
`BKE_object_modifier_stack_copy` instead.

Fix T82945: Crash when dragging modifiers in Outliner.

Maniphest Tasks: T82945

Differential Revision: https://developer.blender.org/D10148

Refactor modifier copying code.

Things like pointers to particle systems, or softbody data being stored
outside of its modifier, make it impossible for internal modifier copy
data code to be self-contained currently. It requires extra processing.

In existing code this was handled in several different places, in
several ways, and alltogether fairly inconsistently. Some cases were
even not properly handled, causing e.g. crashes as in T82945.

This commit addresses those issues by:
* Adding comments about the hackish/unsafe parts `psys` implies when
copying some modifier data (since we need to ensure particle system
copying and remapping of those pointers separately).
* Adding as-best-as-possible handling of those cases to
`BKE_object_copy_modifier` (note that it remains fragile, but is
expected to behave 'good enough' in any practical usecase).
* Remove special handling for specific editor code
(`copy_or_reuse_particle_system`). This should never have been
accepted in ED code area, and is now handled by
`BKE_object_copy_modifier`.
* Factorize copying of the whole modifier stack into new
`BKE_object_modifier_stack_copy`, now used by both `object_copy_data`
and `BKE_object_link_modifiers`.

Note that this implies that `BKE_object_copy_modifier` and
`BKE_object_copy_gpencil_modifier` are now to be used exclusively to
copy single modifiers. Full modifier stack copy should always use
`BKE_object_modifier_stack_copy` instead.

Fix T82945: Crash when dragging modifiers in Outliner.

Maniphest Tasks: T82945

Differential Revision: https://developer.blender.org/D10148

Merge branch 'blender-v2.92-release'

Fix T84739: Crash with curve brush in sculpt mode.

No idea why we did not pass context to `ED_paintcurve_undo_push_end`, it
is easily availbale everywhere...

Fix T84758: Revert "LibOverride: Also consider regular embedded IDs as virtual overrides."

This made Blender considers all materials to be overridden.

This reverts commit 2aa7bc06e7a6adb196e552fca3289ed7b7a18f3f.

Cleanup: LibOverride: Update comment.

LibOverride: Also consider regular embedded IDs as virtual overrides.

Those (aka root node trees and master collections) share same 'traits'
as the shapekeys: RNA cannot assign them, so we need to handle them as
sub-data of their owner IDs.

Not sure how much this will help in improving support of overrides for
scenes and nodetrees, but this is a mandatory step towards that goal for
sure.