[FEAT] Add collisional heating terms

[aaronjridley]

Is your feature request related to a problem? Please describe.
Joule heating, frictional heating, and heat transfer are key processes and are symmetric in the different equations. Additionally, the momentum transfer terms are symmetric. So, there should be a general place to do these calculations that are agnostic as to the planet.

Describe the solution you'd like
Functions that calculate the general form of the collisional heating and momentum transfer terms. Then specific calls with the ions, neutrals, and electrons.

Describe alternatives you've considered
The real question is whether we will have one ion velocity or ion velocities for each species. Same for temperatures. I don't know how stiff the equations are for the heat transfer, so I don't know whether this is easy to implement or not. For now, I would consider individual velocities and one temperature for bulk ions.

Additional context
Nope.