refactor: Refactor public parameters setup to remove optionality of commitment key size hint

[huitseeker]

Context

See #5 and microsoft/Nova#203, by which public parameter creation takes a size hint. This size hint carries the particular requirements of the final compressing SNARK the user expected to use with these public parameters.

This avoids setting the size of public parameters too conservatively for all users of the code base, but rather limits the use of "big" public parameters to those constructions that will eventually need them.

In this PR

We slightly simplify the API of passing a commitment key size hint when creating public parameters. We apply this to Supernova, closing #53.

Companion Lurk PR at lurk-lab/lurk-beta#843

In detail

• Converted CommitmentKeyHint<G> from a boxed dynamic trait object to a direct dynamic trait object in r1cs/mod.rs.
• Changed the commitment_key function to always require a commitment key floor, eliminating the need for default behavior when a floor function isn't provided.
• Updated the r1cs_shape function across various files to take in a CommitmentKeyHint instead of it being optional and introduce a closure as an argument.
• Relevant modifications and updates were made in the r1cs_shape and commitment_key function calls within the test functions for various modules.
• Ported use of commitment key hint to Supernova, closing Manage CommitmentKeyHints properly in supernova #53.
• This PR puts Arecibo in line with the latest state of feat: Make commitment key generation configurable with an optional parameter microsoft/Nova#203

[adr1anh]

Changes look good to me. Only noted a typo in the comments.

Idea: Define a default CommitmentKeyHint which just returns 0, instead of having &(|_| 0).

[huitseeker]

Idea: Define a default CommitmentKeyHint which just returns 0, instead of having &(|_| 0).

Done!

[mpenciak]

Looks good other than a small unimportant naming thing!

[adr1anh]

All looks good to me!