Rust SDK: rename to_base58_check to to_b58check for Signature

What

This MR implements to_b58check and from_b58check for tezos_crypto_rs::signature::Signature

Closes SDK-73

Why

In sdk_bindings::keys, the macro bind_hash! is used to binds hashes based structures. This macro use to_b58check and from_b58check in its process. Therefore, in order to, also, use this macro for signature::Signature (instead of manually implements the binding), to_b58check and from_b58check have to be implemented for signature::Signature.

How

By aliasing the existing function to_base58_check (resp. from_base58_check) to to_b58check (resp. from_b58check)

Manually testing the MR

Checking that hash bindings are still valid by launching the nix environment:

cd contrib/sdk-bindings
nix-shell

and running all tests:

make test

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR