Remove the custom error / rejection handling for routes in Delta

**Motivation**
This was the case because back when we were using Monix BIO not all errors were exceptions.
Now that they all are we can rely on the `ExceptionHandler` and `RejectionHandler` provided by akka

**Acceptance criteria**
1. There is no impact on error/rejection handling
2. Code should be simplified

This section should be about results in domain terms, not implementation details.

**Implementation notes**
* Every plugin will have to register its `ExceptionHandler` (it should be easy with Distage)
* `ResponseToJsonLd` should only take care of the success path

Start by locating the route error and rejection handling and the ResponseToJsonLd component mentioned in the issue. Check how each plugin registers its ExceptionHandler and RejectionHandler, then verify that removing the custom handling preserves error and rejection responses while leaving ResponseToJsonLd responsible only for successful results.

Written by the indexing model from the issue text.