Cleanup: LibQuery: Rename `BKE_LIB_FOREACHID_PROCESS` to `BKE_LIB_FOREACHID_PROCESS_IDSUPER`.

More in-line name with the rest of that macro-based API, especially
since this will be extended in the future.

Cleanup: `else` after `continue`.

Fix crash in liboverride/pointcache handling code after recent changes.

In some cases code would try to access NULL pointer.

Reported by @dfelinto, thanks.

Cleanup: forgot to remove empty line in previous commit.

Cleanup: build warnings.

`NULL` instead of `nullptr` in cpp code, and `else` statements after
returns.

Fix non-capitalized UI message.

Fix T92430: Infinite recursion in some cases in new append code.

Shapekeys, always shapekeys... Since we cannot deal with them as regular
IDs, we need to handle potential recursion cases ourselves here. sigh.

Fix T92290: Linked Color Palette datablocks can not be used.

* Forbid editing linked palettes.
* Make `color` RNA property of ColorPalette '`LIB_EXCEPTION`', so that
the color buttons in the palette template remain active on linked data.

NOTE: This incidently makes linked palettes' colors editable from RNA,
not from UI though, so think this is OK for now.

Fix T90638: Inconsistent object data behavior when link-duplicating collections.

Camera, lattice and speaker object types were missing there own proper
`USER_DUP_` flags, leading to not properly handling duplication of their
object data.

NOTE: We could probably simply opions here, by using categories (like
'GEOMETRY', 'SHADING', etc.) instead of exact object types. But this is
beyond bugfix scope.

Cleanup/Fix (unreported) 'make single user' handling of actions.

Actions of duplicated objects would not be properly made single user,
unlike obdata and materials.

Further more, there is no reason to manually handle such animdata
copying here, `BKE_id_copy_ex` can do that for us with the proper flags.