Blender Git Loki

Drivers Editor UI Tweaks (Part of T55145)

To bring the UI more in line with the proposed design in T54653 for the "Add Drivers"
popup panel (NOTE: this is separate from the "Drivers Editor", in previous commit!),
this commit adds a new panel - "Driven Property" to the Drivers Editor UI.

This basically duplicates the "Active F-Curve" panel (with less options)
to make it easier to see at a glance which property the Drivers Editor is
showing you.