Extend Theta-E and wetbulb calculations to have configurable moist ascent

[keltonhalbert]

This library allows for the configuration of different moist adiabats for parcel ascent, but currently, the theta-e and wetbulb calculations are hard-coded to use the Wobus wetlift approach.

I think the best option is to move theta-e and wetbulb into the parcel library since these are technically parcel routines. Then it will be easy to follow the template style used for the other routines with configurable moist adiabats. This will also require updates to the SWIG wrappers for theta-e and wetbulb.