Add input file validation

[jaredthomas68]

Add input file validation

It would be very helpful to have input validation backed in as a check and a layer of documentation for all HOPP and GreenHEART input files.

Proposed solution

We could do this like WISDEM (https://github.com/WISDEM/WISDEM/tree/master/wisdem/inputs), including default input yaml schemas. We could also do it like FLORIS (https://github.com/NREL/floris) with the attrs class.

Alternatives considered

Right now we are reliant on example yamls, but the examples do not always get updated with code changes

Additional context