New functionality for plot.simmer

[Enchufa2]

Once #11 is implemented, plot.simmer can be reimplemented to plot all resources and generators attached to their trajectories.

[Enchufa2]

Requires r-simmer/simmer#159.

[Enchufa2]

For this to be useful, trajectories should first hold identifiers that are kept when a trajectory is cloned or joined.