HTTP CA Tests

This epic lists automated tests that we ought to create to validate our HTTP CA. This work is of increasing importance, particularly given the work to make the HTTP CA highly available.

QA would like to partner with any available members of the puppetserver development team, and learn how to write clojure unit tests. Having discussed this work with chris , I'm leaving some of the clojure tickets in "open" so that we can discuss them in the next backlog grooming session.

Existing Unit tests are here:
https://github.com/puppetlabs/puppetserver/blob/master/test/unit/puppetlabs/puppetserver/certificate_authority_test.clj

The majority of these proposed tests are tests that used to execute inside the defunct QATests repository; SERVER-1324, 1325, 1326, 1327, and 1329 would introduce new tests, while the rest of the tickets would just create previously existing tests.

Documentation:
https://docs.puppet.com/puppet/latest/reference/http_api/http_api_index.html
https://docs.puppet.com/puppet/latest/reference/http_api/http_certificate.html
https://docs.puppet.com/puppet/latest/reference/http_api/http_certificate_request.html
https://docs.puppet.com/puppet/latest/reference/http_api/http_certificate_status.html
https://docs.puppet.com/puppet/latest/reference/http_api/http_certificate_revocation_list.html