The prefixing logic is moved into a `prefixProtocol` function in lib:url.
This commit also renames an incorrectly named test and uses https as default instead of http, in 2020 it's reasonable to think we most likely want https and not http. User can still specify http if required.
We used many global functions to handle tests when they should be
imported like other libraries in our application. This also gets us
closer to the way Ember CLI prefers our tests to be laid out.
This is where they should be as far as ember is concerned. Note this is
a huge commit and we should be really careful everything continues to
work properly.