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##### SUMMARY
Allow to specify a new "format" parameter in "openssl_privatekey". Today the output format is decided by a very simple heuristic which requires further commands to work properly.
I need, for example, to generate a RSA private key but in PKCS8 format. The current heuristic uses OpenSSH format for RSA keys and only uses PKCS8 for Ed25519 and similar. This makes me use a "command" with "openssl" to convert the generated key, which leads to idempotency problems and unnecessary complexity.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
openssl_privatekey

##### ADDITIONAL INFORMATION
<!--- Describe how the feature would be used, why it is needed and what it would solve -->
The current heuristic should be kept unless overwritten by user.

<!--- Paste example playbooks or commands between quotes below -->
```yaml
openssl_privatekey:
  path: /etc/ssl/private/ansible.com.pem
  format: pkcs8
```
The values allowed are `pkcs1`, `raw` and `pkcs8`

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"""Generate the fingerprint of the public key. """
    privatekey = load_privatekey(path, passphrase, check_passphrase=False)
    try:
        publickey = crypto.dump_publickey(crypto.FILETYPE_ASN1, privatekey)
    except AttributeError:
        
        try:
            bio = crypto._new_mem_buf()
            rc = crypto._lib.i2d_PUBKEY_bio(bio, privatekey._pkey)
            if rc != 1:
                crypto._raise_current_error()
            publickey = crypto._bio_to_string(bio)
        except AttributeError:
            
            
            return None
    return get_fingerprint_of_bytes(publickey)
def load_privatekey(path, passphrase=None, check_passphrase=True, content=None, backend='pyopenssl'):