Blender Git Loki

UI: Move properties tab list creation from RNA to editor

This is a change I pulled from the property-search-ui branch,
where I have to use the list of tabs to search the inactive tabs
and it makes more sense to use the array directly.

It is also an improvement to have this fundamental code to the
properties editor in the editor code rather than an RNA callback.

There are no functional changes.

Differential Revision: https://developer.blender.org/D8368