Add ability to specify message length as a witness for all hash functions

[kevaundray]

Problem

See Issue #313 for the Keccak variant.

This however makes Keccak seem special when infact this property can be applied to all hash functions, albeit they will be implemented differently internally since not all hash functions are sponge_absorb.

Happy Case

Add the ability to specify the message length as a witness for all hash functions

Alternatives Considered

No response

Additional Context

No response

Would you like to submit a PR for this Issue?

No

Support Needs

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[TomAFrench]

Closing as we're changing to implementing the internal sponge functions rather than a monolithic version which takes an arg.