Add trajectory plotting functions from SPARKLING

[chaithyagr]

There are a bunch of scripts to better view k-space sampling trajectories, particularly but not limited to 3D:

• Temporal colored plots: Helps to verify how good trajectory is with respect to off-resonance
• K-space sampling density plots: Helps identify k-space sampling holes
• Plotting only a bunch of shots within a range etc.
• Have a gallery of trajectories presented based on above details. It should be automatic generation from the trajectories library

Ideally, we need a script to handle this and this can be a good GUI to handle most of what we need (with or without the help of napari).
@paquiteau Opinions?

[paquiteau]

Fee free to open a PR. I guess we will need nice examples to show off this great work. Also be sure to check what is already feasible from the work of @Daval-G, there might be some redundancy between what you propose and what is already there (I am thinking about the "plotting only a bunch of shot" notably)