Handling `Type`

[yalhessi]

CoqSynth doesn't support synthesizing an expression of type Type (it does return a result but it's unclear how it's incorrect without unification). Lfind also doesn't handle Type variables.

[yalhessi]

The first major issue we run into here is with example generation. I'm not sure if it's necessary here to monomorphize in able to generate example (see https://softwarefoundations.cis.upenn.edu/qc-current/QuickChickInterface.html)

It looks from looking at https://softwarefoundations.cis.upenn.edu/qc-current/QC.html that QC could be able to handle polymorphic data types