Add support for quick help in monaco-json

I would like to add support for quick help in JSON language support if a JSON schema is provided for the JSON file the user is editing. Here is an example:

It’s possible to implement it using overlay widgets but the language support doesn’t work on the main thread and instead runs under the LSP. Ideally, we can send a message from the WebWorker to the main thread and create an overlay widget for the editors if a flag is enabled.

The main problem is that the LSP doesn’t really have an access to the editor, I can work on this feature and create a PR on monaco-json if there’s interest, I already have a prototype but couldn’t really find a way to make this feature embedded into monaco-json as we don’t have access to the created editors. Instead, I’m creating an overlay widget in my editor separately talking to the language server.

[aeschli]

IMO adding to monaco-json is not the right approach as this is quite a specific feature. Instead you could be looking into having your own monaco-json and replace the original one.

[buremba]

I forked monaco-json and implemented getSchema(uri: Uri, position: Position)``monaco.languages.json.getWorker() and implemented an overlay widget using json-schema-visualizer. It looks to be the convenient way for this use-case. Thanks!