Move "Camera Parent Lock" from preferences to Object Relations

"Camera Parent Lock" can be useful when rigging cameras, but it is not
intuitive, and has also generated a lot of confusion (bug reports).
This is because it breaks the fundamental parent <-> child relationship
conventions in Blender, and there is no indication that it's intended
without diving into the preferences.

This commit moves the setting to the object level, and exposes it in
the relations panel in the property editor. It is exposed for every
object type because any object type can be "View Locked" in the 3D view.
The property description is also updated to reflect this change and be
more specific without getting too long.

In the future this could become a more general feature of the transform
system, but for now it is limited to "Lock Camera to View".

Differential Revision: https://developer.blender.org/D9239

release/scripts/startup/bl_ui/properties_object.py

@@ -141,6 +141,7 @@ class OBJECT_PT_relations(ObjectButtonsPanel, Panel):
         if parent and ob.parent_type == 'BONE' and parent.type == 'ARMATURE':
             sub.prop_search(ob, "parent_bone", parent.data, "bones")
         sub.active = (parent is not None)
+        sub.prop(ob, "use_camera_lock_parent")
 
         col.separator()