Blender Git Loki

Separate operators (mesh/curve/armature/gpencil): take user preferences
into account for duplicating actions

Previously actions remained linked after duplication, now this is based
on the User Preferences (PreferencesEdit.use_duplicate_action).

note: default is ON here, so this changes default behavior of separate
operators.

First intuition was to respect _all_ preferences here (e.g. also
duplicating materials if chosen in the User Preferences) but after
consideration this is probably not what the User would expect from such
'modeling' opertions (e.g. separate by loose parts resulting in possibly
many duplicate materials)

Fixes T71038

Maniphest Tasks: T71038

Differential Revision: https://developer.blender.org/D6120