tests: Add Wycheproof ECDSA vectors

[RandomLattice]

This PR adds a test using the Wycheproof vectors as outlined in #1106. We add all 463 ECDSA test vectors. These vectors cover:

• edge cases in arithmetic operations
• signatures with special values for (r,s) that should be rejected
• special cases of public keys

The vectors are pulled from the Wycheproof project using a python script to emit C code.

All the new ECDSA Wycheproof vectors pass.