Add animation capabilities

[tygamvrelis]

This PR brings in animation features. Three types of animations are available:

1. Top-down -- bird's eye view of the lamp motion

2. Pendulum -- view of the lamp motion "from the side"

3. Phase -- visualizes the angles of the gimbals as a function of time

4. and 3. support visualization of the motion vectors, so that contributions from the base and lamp IMUs can be distinguished.

Before bringing this in:

• double-check that sign conventions are consistent (i.e. do negative and positive have consistent meanings for all the animated quantities?)