Blender Git Loki

Drivers UI (Part of T55145): Add "Show Drivers Editor" entry to RMB menus

This commit adds an operator, "Show Drivers Editor", to the RMB menu when
clicking on properties.

As per T54653, this will open a new Graph Editor instance in a new/separate
window (much like how the User Preferences show up in a popup window now),
and will configure all the relevant panels so that you can see and edit the
driver settings immediately without doing a lot of the view configuration steps
that were previously needed.

When doing so on a property that is driven, the driver/fcurve for that property
will be made active in the editor, ready for you to start editing its settings
without having to hunt it down again first.