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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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pass
class OpenSSLBadPassphraseError(OpenSSLObjectError):
    pass
def get_fingerprint_of_bytes(source):
    """Generate the fingerprint of the given bytes."""
    fingerprint = {}
    try:
        algorithms = hashlib.algorithms
    except AttributeError:
        try:
            algorithms = hashlib.algorithms_guaranteed
        except AttributeError:
            return None
    for algo in algorithms:
        f = getattr(hashlib, algo)
        h = f(source)
        try:
            
            pubkey_digest = h.hexdigest()
        except TypeError:
            pubkey_digest = h.hexdigest(32)
        fingerprint[algo] = ':'.join(pubkey_digest[i:i + 2] for i in range(0, len(pubkey_digest), 2))
    return fingerprint
def get_fingerprint(path, passphrase=None):