Add UI schema to task discovery response to help frontend build forms

Feature request

Description

Regarding this issue about validating tasks https://github.com/open-rmf/rmf-web/issues/684. Afaik, there are several blockers for us to resolve it.

• The rmf task discovery endpoint is not implemented yet
• The task discovery uses json schema to describe the params of a task
  • Problem is that json schema is very powerful/flexible, I have tried building a form from json schema before but there are too many features which makes the whole process super complicated.
  • There are some similar OSS projects like https://jsonforms.io/ and https://github.com/rjsf-team/react-jsonschema-form, but they require a ui schema to be written beforehand so it won't quite work for our case. Given that this is the approach they use, my conclusion is that going from json schema -> ui forms directly is actually a very complex challenge.

My proposal is to have task discovery contain both the json schema and a ui schema, with this, we can build forms for any tasks and validate them.

Start by examining how the task discovery endpoint is represented in this repository and how task parameters are currently described with JSON Schema. Define what the combined JSON Schema and UI schema response should contain, then verify that it supports frontend form generation and task validation.