[WIP] Create custom behavior for RouteNotFoundException

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | no
| Fixed tickets | #10
| License       | MIT
| Doc PR        | need to be done

That's my starting point to work on this issue.

was my first idea, but will change it to the `kernel.exception` event now, cause this solution does not work.