UI: Revert last four commits

These were an oversimplification of orbit movement since that
transpires over elliptical paths for which the rodriguez
simplification does not apply.

Reverts these inorder to devise an alternative strategy
UI: load orbit angle once and update from there on out

Optimizes use of orbit by calculating orbit angle on init and
then simply updating stored value instead of recalculating
on every update.

Adds a TODO to optimize orbit furthur by combining orbit
plane & axis rotations into a single rotational matrix/operation
UI: fix tests broken by last commits

Mostly reverted commit #02cce43760 applied against the latest head
incorporating the updates to the orbit api
UI: add station gfx children to mesh instead of scene

Optimizes gfx operations as individual entities do not have
to be updated on location updates
UI: few followup optimization fixes to planet
UI: componentize station gfx for optimizations

Optimizes station gfx (and the progress bar) by splitting
up operations so that only the necessary data is updated when it
is needed.

Tests updated to reflect new functionality