Picker could also support JSON Schemas

Brought up in a meeting today. I am very unsure about this idea. I like it, but I really wonder how complex this would get. Instead of say 10 documents, we would then load a schema and display the structure it defines.

Considerations to make:

- The amount of work required
- Do we lose something if we do this?
- If someone would need metadata for multiple documents per record as input, for JSON it is easy to combine them to one document. For multiple JSON Schema, though, this would need to be evaluated. Also, if we have one document and two schemas, I am not sure what to do.
- ...

Definitely not a feature for the prototype state, but maybe for a 2.0.0?

No files, tests, or entry points are named. Start by reviewing the existing Picker flow and prototype constraints, then assess how loading and displaying JSON Schema structures would interact with multiple documents, multiple schemas, and combined JSON input. Done should be defined as an agreed scope and behavior for a future implementation.

Written by the indexing model from the issue text.