Refactor ide-helper generator

Make some changes to make it easier to work on / understand.

TODO:
 - [x] Use PSR-4
 - [x] Use Views to render output
 - [x] Seperate logic from the command
 - [x] Use DI instead of Facades
 - [x] Add config for interfaces (#93)
 - [ ] Detect interfaces automatically if possible?
 - [ ] Tests?