* add renderSizeBadge helper, use it everywhere
- switch from pretty-bytes to byte-size
- add renderSizeBadge() helper function
- match upstream conventions for metric/IEC units
- add new test helpers and use them in service tests
* unrelated: fix npm unpacked size query param schema
not strictly related to this PR
but I noticed it was broken
* chromewebstore: reformat size string, test against isIecFileSize
* Modify github-size.service.js
* Add tests for Github Size Service to test the new ref parameter
* Modified request for a file size: ref is now sent only if if was specified
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.
