[pfsense_ca] Add ability to create a certificate authority, not just import one

[samuel-emrys]

Is your feature request related to a problem? Please describe.
It would be good to be able to create a certificate authority rather than just import one, as is supported by the pfSense web gui. This would allow a fresh installation to easily be managed without manual intervention to configure certificates.

Describe the solution you'd like
The following syntax would create a certificate authority:

- name: Create CA
  pfsensible.core.pfsense_ca:
    name: root-ca
    method: internal
    trust_store: true
    randomize_serial: true
    key_type: rsa
    key_length: 2048
    digest: sha256
    lifetime: 3650
    common_name: internal-ca
    country: us
    state: texas
    city: austin
    org: my org
    org_unit: my department

Describe alternatives you've considered
N/A

Additional context
N/A

[opoplawski]

PRs welcome. I think this will require some investigation of what PHP functions need to be called to create the cert/key and anything else required to setup the CA.