refs #9178
* Moved app handling code into services/apps
- Apps is a service, that allows for the App lifecycle
- /server/apps = contains internal apps
- /server/services/apps = contains code for managing/handling app life cycle, providing the proxy, etc
* Split apps service tests into separate files
* Moved internal app tests into test folders
- Problem: Not all the tests in apps were unit tests, yet they were treated like they were in Gruntfile.js
- Unit tests now live in /test/unit/apps
- Route tests now live in /test/functional/routes/apps
- Gruntfile.js has been updated to match
* Switch api.read usage for settingsCache
* Add tests to cover the basic App lifecycle
* Simplify some of the init logic
