Operation request: Sign/Verify with EdDSA

## Summary
Similar to RSA, support "Sign with EdDSA" and "Verfiy with EdDSA"

### Example Input
the needed key for the operation (sign=>private key | verify => public key) as PEM

for sign the message is the input
for verify the signature is the input (and the message is provided as option)

### Example Output
for sign: the signature
for verify: the verification result

Start by locating the existing RSA signing and verification operation and reviewing how its PEM keys, message or signature input, and options are handled. Add equivalent EdDSA sign and verify behavior, with signing returning a signature and verification returning the verification result, then run the related operation tests if available.

Written by the indexing model from the issue text.