Wip/large layout refactoring

Not Ready Yet.

Here is the micro roadmap for this PR:
- remove panel ✔ (407)
- add tutorial in navigation tab ✔ (407)
- apply new layout to run, inspect, test ✔ (PR 403 -> 406)
- put panels back and finalise tutorial ✔ (407)
- cleanup layout
- new code plugin