Add user-facing function which kicks off all input preparation

[danielolsen]

:rocket:

• [x] Is your feature request essential for your project?

Describe the workflow you want to enable

I wish there was one entry point, to which the user provided all required information, which launched all lower-level Switch input preparation functions. This was prompted by conversations in #52.

Describe your proposed implementation

This function will take as arguments the superset of all arguments that get passed to grid_to_switch and profiles_to_switch--avoiding repetition of input parameters such as the Grid object, the output folder, and the year(s) for capacity expansion optimization--and produce all files relevant for running Switch and for eventually processing the outputs (e.g. a saved representation of the input Grid object). After this step, the only remaining step to launch a simulation should be running the script developed for #52.

[danielolsen]

As mentioned in #64, this would be the appropriate place to perform a check that the provided Grid and profiles match: the generation profile columns should match the indices of the generators of the corresponding type within the grid.plant table, and the demand profiles columns should match the corresponding zone IDs within grid.bus.