Convenience functions for common plots?

[sfmig]

Is your feature request related to a problem? Please describe.
A few times we have discussed whether it would be useful to include convenience functions to produce plots that are common or cumbersome to write.

For example we could have plot_trajectory or plot_trajectory_with_velocity_vectors.

One implementation @niksirbi liked a while ago is the one in pyrat

Describe the solution you'd like
A plotting module that is part of movement, with helper functions for plotting and/or utils for producing common plots.

Describe alternatives you've considered
We may just use xarray's plot method and matplotlib directly as we do now.

It may be that our users end up doing their own custom plots anyways, and aiming to cover them all is quite ambitious. Right now our examples are a good showcase of how to make informative plots with a movement dataset.

We may also end up delegating these things to napari-matplotlib.