Generalized Wind Input

[jklenzing]

Is your feature request related to a problem? Please describe.
Multiple HWM models are currently included to look at a variation of parameters, however, the general shape of all three models are usually the same. To investigate the effects in a more systematic manner, there should be an option to input a mathematical description of the winds, similar to the fourier series input for ExB drifts.

Describe the solution you'd like
Ideally

• Remove the alternate wind models
• Specify HWM14 as the default
• Incorporate some mathematical function to calculate alternate winds.

Additional context
The ExB drifts were relatively simple to implement due to field-line mapping. Winds would potentially be a three-dimensional function (lat, slt, alt). Larger discussions are needed to determine what behaviour would be needed.