Make Image quality settings configurable

__Tasks:__

- [x] test coverage
- [x] gather feedback for my changes
- [x] submit changes to the documentation
- [x] extract formats out off image converter
- [x] add formats to format manager
- [x] append quality and compression level to image options


__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | yes
| Fixed tickets | fixes #658 
| BC Breaks     | none
| Doc           | https://github.com/sulu-cmf/docs/commit/577da8d22504e732b81cf235dc5c9a4b10a3c56a