Migrate Tests to be HTTP Based

[confused-Techie]

This PR migrates a huge number of our tests to be HTTP based only, instead of manually calling the specific functions (e.g. endpoint.logic()) of each endpoint.

Doing this means we are moving tests to the only contract the backend has, it's actual API.

The reason we need to do this is that we can begin modifying the way we interact with endpoints without having to rewrite tests each time, and means we more reliably are testing exactly the output users get.

Doing this en-mass is a precursor to being able to do something like #293 more widely.

Since this is a test only change, as long as everything passes we should be golden, the methodology we use is already in use in this codebase, we are just using it more than before.

EDIT:::

You'll also noticed I added a new DB method, for deleting a user. This is currently inaccessible via the API, but allows us to preform proper cleanup during HTTP based tests, and eventually we really should make it accessible via the API.

[confused-Techie]

Seems the errors reported by Codacy are a false negative.

Based on the other recent PRs here I fear there's nobody available to provide a review at this time.
And because this PR is to serve a larger purpose, I'll go ahead and merge it into the feature branch v1.2 and continue to work in there until all changes are ready for production at which point it's easier to wait more patiently for a review.

But having this as PR helps to visualize that tests are all still passing even after significant modification.