More testing for sign/verify through `dgst`

More testing for sign/verify through `dgst`

Add tests for signature generation and verification with `dgst` CLI for
common key types:
- RSA
- DSA
- ECDSA

(cherry picked from commit ef1e59ed833e8ed1d5f4de5b0c734da8561890e3)

This is a backport from https://github.com/openssl/openssl/pull/10410.
Support for testing EdDSA through `pkeyutl` was dropped as the required
`-rawin` option is not supported in 1.1.1.

Fixes #10687

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/11939)