* certutil: select appropriate hash algorithm for ECDSA signature
Select the appropriate signature algorithm for certificates signed
with an ECDSA private key.
The algorithm is selected based on the curve:
- P-256 -> x509.ECDSAWithSHA256
- P-384 -> x509.ECDSAWithSHA384
- P-521 -> x509.ECDSAWithSHA512
- Other -> x509.ECDSAWithSHA256
fixes#11006
