Add five new Wycheproof ECDSA test vectors using IEEE P1363 format

[Sajjon]

This PR is branched from source branch of https://github.com/apple/swift-crypto/pull/166, so please do review and merge that first.

Add five new Wychyeproof ECDSA test vectors using IEEE P1363 format

Checklist

• [x] I've run tests to see all new and existing tests pass
• [x] I've followed the code style of the rest of the project
• [x] I've read the Contribution Guidelines
• [x] I've updated the documentation if necessary

If you've made changes to gyb files

• [ ] I've run .script/generate_boilerplate_files_with_gyb and included updated generated files in a commit of this pull request

Motivation:

We ought to use as many and as up to date test vectors as possible. Wycheproofs v0 were created 4 years ago and were due some upgrade.

Modifications:

1. Removed 4 unused test vectors: ecdh_test, ecdh_webcrypto_test, ecdsa_test, ecdsa_webcrypto_test
2. Added 5 new test vectors: ecdsa_secp256r1_sha256_p1363_test, ecdsa_secp256r1_sha512_p1363_test, ecdsa_secp384r1_sha384_p1363_test, ecdsa_secp384r1_sha512_p1363_test, ecdsa_secp521r1_sha512_p1363_test.
3. Update ECDSASignatureTests renaming testWycheProofEdDSA -> testWycheproofEdDSA, testWycheProofP256 -> testWycheproofP256DER and analgously for P384 and P521.
4. Update ECDSASignatureTests with three new unit test functions testWycheproofP256P1363 testWycheproofP384P1363 testWycheproofP521P1363

Result:

(252 + 322 + 270 + 308 + 308 =) 1460 new tests are being run for ECDSA.

[Lukasa]

Hrm, this will need to be cleaned up to merge nicely on the patch we just landed. I'm inclined, in general, to try not to add new test files here: I think keeping them merged together is reasonable.

[Sajjon]

@Lukasa ok I will rework the PR a bit and try first not adding any init test swift files

What about my removal of the 4 unused test vectors, are you OK with that?

[Sajjon]

@Lukasa I've reverted the unit test file changes, and updated the description in the PR to reflect the modifications => ready for re-review.

[Lukasa]

@swift-server-bot test this please