Move to hashlib for hashing

[nielstron]

Is your feature request related to a problem? Please describe.
pycardano currently uses NaCL for its hashing primitives. This is usually a large library, that is also not pure python and often causes long builds during installation.

Describe the solution you'd like
The python standard library hashlib supports sha256 etc. It would be nice if they can be used by default.

Describe alternatives you've considered
None

Additional context
I want to make development on Cardano as accessible as possible and a short and easily installable toolchain is part of that.

[cffls]

We use NaCL also for signing&verification on curve ED25519, such as this example here. Do you have some alternative libraries in mind that can do both signing and hashing? I can look into them.

[nielstron]

I realized that NaCl is used for signing too... Will check if there are lightweight alternatives :)