Feature request: Support Ed448

[marek22k]

OpenSSL seems to support Ed448. When I try to import a ed448 key, I get:

The following error occurred:
The key from file 'private.pem' is incomplete or inconsistent.

and

The file 'provate.pem' did not contain PKI data

I also get an error dialog when I try to import a certificate with is signed by a ed448 key.

[ingria]

Same error for ed25519 key