[WIP] Split View for contact

Split View for contact:

__Tasks:__

- [ ] test coverage
- [ ] gather feedback for my changes
- [ ] submit changes to the documentation
- [ ] implement widgets
- [ ] integrate split view area


__Informations:__

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| Tests pass?   | yes
| Fixed tickets | none
| Doc           | https://github.com/sulu-cmf/docs/blob/master/developer-documentation/000-foundation/create-a-pull-request.md