Allow robot solutions to be selected for joint move instructions

The joint move instruction currently moves to the target by following the shortest path, according to the solver. However, for any given target, there may be several valid solutions within the constraints of the joint limits.

When configuring a joint move instruction, users should be able to preview and select from a list of solutions that the solver was able to find. This will ensure that the user can select an appropriate configuration for the joint angles.

This feature was added to v0.22.