Rsa suite6 tests

[ValentinVaninetti]

##Summary
Adds 6 integration tests for RSA sign/verify, encrypt/decrypt, and error handling.

##Changes
New Tests (6)

Sign and verify with correct key
Signature rejection on tampered message (edge case)
Signature rejection with a different key (edge case)
Encrypt/decrypt round-trip
Sign with unknown key returns RsaKeyNotFound
Decrypt with unknown key returns RsaKeyNotFound

##New file: src/tests/rsa_test.rs Modified: src/tests/mod.rs (registered new module)

[danielemiliogarcia]

I’d suggest renaming pem ((Privacy-Enhanced Mail)) to pubkey_pem for readability.
The method name generate_rsa_keypair suggests it returns a full keypair, so calling the result pem can be misleading to readers who aren’t familiar with the KeyManager API. Using pubkey_pem makes the intent explicit when verifying the signature.

the same apply for all the tests

[ValentinVaninetti]

Thank you! will do the changes!