This takes another pass over the modern services to remove unused code. I switched the shared code to use a function instead of a class and removed the indirection in the route params which led to skew between the route and examples and wasn't making things any clearer.
This will definitely save time, and ensure more uniformity.
It moves the `createServiceTester()` calls to a different place from where I'd like them, though I'm happy to have them checked by the linter.
Closes#2701
Fixes#2876 with @paulmelnikow's suggestion
Moved imports of `ServiceTester` and `createServiceTester` to a separate file so that dev dependencies are not imported by service classes.
Continue to implement #2698:
- Add `core/base-service/index.js` (but hold off on moving the things it imports)
- Add shortcuts in `services/index.js` for Base*Service, errors, and deprecatedService. This file will be streamlined later to avoid cluttering it with rarely used bits.
- Apply consistent ordering of imports and use of `module.exports` in testers.
- Remove some renaming of imports.
- Remove obsolete tests here and there.
This is a bit of sugar that reduces the boilerplate for creating testers in what I expect will become the standard case: a service in `foo/foo-thing.service.js` with its tests in `foo/foo-thing.tester.js`.
This makes a small stylistic change, which is to name the service by its CamelCase class name rather than an invented snake-case ID. Whereas before the name was specified in `class FooThing extends Base[Json]Service` and a second time in the tester, it now only needs to be specified once.
