[FEATURE] Restructured content for Twig template

__Tasks:__

- [x] test coverage
- [ ] gather feedback for my changes
- [x] submit changes to the documentation
- [x] add test for `StructureResolver`

__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | yes
| Fixed tickets | none
| BC Breaks     | Changed variables available in twig templates
| Doc           | none