csrgen: Automate full cert request flow
Allows the `ipa cert-request` command to generate its own CSR. It no
longer requires a CSR passed on the command line, instead it creates a
config (bash script) with `cert-get-requestdata`, then runs it to build
a CSR, and submits that CSR.
Example usage (NSS database):
$ ipa cert-request --principal host/test.example.com --profile-id caIPAserviceCert --database /tmp/certs
Example usage (PEM private key file):
$ ipa cert-request --principal host/test.example.com --profile-id caIPAserviceCert --private-key /tmp/key.pem
https://fedorahosted.org/freeipa/ticket/4899
Reviewed-By: Jan Cholasta <jcholast@redhat.com>