Add support for plotting vs. `Coordinate`s for `Ligament` Components

[mrrezaie]

Hi, this is merely a suggestion. It would be great if the fascinating Plot vs. Coordinate option exists for OpenSim Blankevoort1991Ligament and Ligament objects. Thank you in advance.

[adamkewley]

I agree that this would be a great feature.

It'll probably come indirectly with a scheduled feature, which will be based on having the Plot vs. Coordinate feature available for all outputs of the model (not just muscles). The feature's scheduled to be worked on after the current major feature (warp tooling)