[RPC] Clean up to_cryptol interface in cryptoltypes.py

[m-yac]

Currently, cryptoltypes.py has the functions to_cryptol, CryptolType.from_python, and CryptolType.convert, all of which do approximately the same thing. Only the first is used in any current code in this repo or in saw-script, so this PR removes the latter two.

Currently, __to_cryptol__ has a CryptolType parameter that does nothing, and to_cryptol has a CryptolType parameter that only matters in the following two cases:

to_cryptol(x, Bitvector(Num(w))) == to_cryptol(BV(w, x)) # if x is an int
to_cryptol(x, Bitvector(Num(w))) == to_cryptol(BV.from_bytes(x, size=w)) # if x is a bytearray or bytes

Otherwise every Python value has a unique CryptolType, so the parameter is unused. These CryptolType parameters are never actually used in any current code in this repo or in saw-script, and I prefer the expressions on the RHS of the equalities above anyway, so this PR also removes these parameters.

NB: This could potentially break someone's code if they use one of the deleted functions or parameters.

[RyanGlScott]

NB: This could potentially break someone's code if they use one of the deleted functions or parameters.

In that case, do mention these changes in the CHANGELOG.

[pnwamk]

LGTM module the one comment regarding possibly keeping the methods on CryptolType