`pretty` query option for JSON response

When querying the API, the response is minimalized and hard to read for human.
Certain server/API offer an option to write "pretty" JSON - JSON that is human readable.
While it should be an option (because it uses more bandwidth), it's useful for debugging, and we might want to support it.

Start by locating the API query handling and JSON response serialization, then inspect how existing query options are parsed. Done means an optional pretty-response setting produces human-readable JSON while the default remains minimal; verify the behavior with the project's relevant API tests.

Written by the indexing model from the issue text.