Design work for adding dns/http tests

[apertome]

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Also need to figure out a good way to add these via raw JSON definitions, if possible

[apertome]

Design work for what adding dns/httpd tests might look like.

1. How to add these necessary fields/logic to the UI
2. Adding new fields to the model (on backend)
3. Adding new fields/logic to the REST API
4. Adding new test types to the Publisher (for outputting these tests)