refactor(credential-w3c): remove hardcoded proof formats

[nickreynolds]

What issue is this PR fixing

• Currently, it's impossible to add support for new proof formats without forking Veramo because the different logic for each supported proof format is hard-coded into credential-w3c

What is being changed

• A new package (credential-jwt) was created to pull JWT-specific logic out of credential-w3c
• The CredentialIssuer plugins (credential-jwt, credential-ld, credential-eip712) now implement a new shared interface (IProofFormatIssuerVerifier) to allow credential-w3c to call appropriate agent functions without knowing their names
• credential-w3c constructor now accepts an array of IProofFormatIssuerVerifier plugins and iterates over them to perform the correct logic when creating or verifying credentials or presentations

Quality

Check all that apply:

• [ ] I want these changes to be integrated
• [X] I successfully ran pnpm i, pnpm build, pnpm test, pnpm test:browser locally.
• [X] I allow my PR to be updated by the reviewers (to speed up the review process).
• [X] I added unit tests.
• [ ] I added integration tests.
• [ ] I did not add automated tests because _____, and I am aware that a PR without tests will likely get rejected.

Note

this is an alternative refactor to #1394

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 92.78729% with 59 lines in your changes missing coverage. Please review.

Project coverage is 89.73%. Comparing base (2110590) to head (04ad9e5).

Files	Patch %	Lines
.../credential-jwt/src/agent/CredentialProviderJWT.ts	95.59%	16 Missing :warning:
...ntial-eip712/src/agent/CredentialProviderEIP712.ts	81.57%	14 Missing :warning:
packages/utils/src/did-utils.ts	12.50%	14 Missing :warning:
packages/credential-w3c/src/action-handler.ts	89.91%	12 Missing :warning:
packages/credential-ld/src/CredentialProviderLD.ts	96.72%	2 Missing :warning:
...s/credential-ld/src/suites/JsonWebSignature2020.ts	80.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## next #1395 +/- ## ========================================== - Coverage 89.79% 89.73% -0.06% ========================================== Files 176 177 +1 Lines 27791 26848 -943 Branches 2208 2220 +12 ========================================== - Hits 24954 24092 -862 + Misses 2837 2756 -81 ```

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