Add pyk support for terms with parametric sorts

[tothtamas28]

In compiled.json, parametric sorts are represented without structure:

{"node":"KSort","name":"MInt{8}"}

We should either parse these, or modify the JSON format on the Frontend.

For such sorts, KORE-to-KAST attempts to instantiate a sort with an invalid name, thus raises an exception.

ValueError: Expected identifier, got: SortMInt{8}

In KORE-to-KAST, the parameter is truncated:

kore = KoreParser('\dv{SortMInt{Sort8{}}}("0p8")').pattern()
print(kore)
>>> DV(sort=SortApp(name='SortMInt', sorts=(SortApp(name='Sort8', sorts=()),)), value=String(value='0p8'))
kast = kore_to_kast(defn, kore)
print(kast)
>>> KToken(token='0p8', sort=KSort(name='MInt'))