Add dedicated EdDSA verifier crate

[PhilippGackstatter]

Description of change

Add a dedicated EdDSA verifier crate which contains a single verifier for curve Ed25519 but could be extended non-breakingly to also support Ed448 later. Other verifier crates could be nicely added alongside it.

This PR also makes the validators fully agnostic over the verifier and not rely on the EdDSA JWS Verifier as the default. Previously the verifier was required even when not using it due to how we used generics. That was changed and the validation methods that don't rely on a verifier were moved to "Util" namespaces. The same applies to the Wasm bindings.

Links to any relevant issues

n/a

Type of change

Add an x to the boxes that are relevant to your changes.

• Bug fix (a non-breaking change which fixes an issue)
• Enhancement (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Fix

How the change has been tested

Existing tests & clippy.

Change checklist

Add an x to the boxes that are relevant to your changes.

• I have followed the contribution guidelines for this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[abdulmth]

Conflicts and some comments.