Rotation node overhaul, editor quality of life

[mbrea-c]

Rotation node overhaul

Improved configurability of rotation node:

• Input rotation can either replace or compose with existing bone rotation.
• Input rotation can be provided in either parent bone, character or global space.
• Input rotation can propagate to parent bones with decaying weight (see chain lenght and chain decay). This avoids artifacts when setting the rotation of a character's head to make it look at something, for example.
• Starting weight of rotation propagation chain can be specified.

Editor quality of life

Various changes which improve the user experience of the editor:

• Scene hierarchy preview shows all of the bones being animated by the animation graph player selected in the preview.
  • Selecting a bone in the scene hierarchy preview will highlight it in the preview window using gizmos.
  • Selecting a bone in the scene hierarchy preview will copy its EntityPath to the clipboard.
• Some nodes can debug draw their effects while selected. For example, the two-bone IK node will draw the old position of affected bones in red, and the new position in blue.
• Graph and scene selectors now take the form of a collapsible tree rather than a flat list.