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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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'''
    Given a list of key usage identifier strings, returns the parameters for cryptography's x509.KeyUsage().
    Raises an OpenSSLObjectError if an identifier is unknown.
    '''
    params = dict(
        digital_signature=False,
        content_commitment=False,
        key_encipherment=False,
        data_encipherment=False,
        key_agreement=False,
        key_cert_sign=False,
        crl_sign=False,
        encipher_only=False,
        decipher_only=False,
    )
    for usage in usages:
        params[_cryptography_get_keyusage(usage)] = True
    return params
def cryptography_get_basic_constraints(constraints):