Make jupyterlab-lsp support the concept of project

[dclong]

Elevator Pitch

When developing a Python project,
configuration files of linters are placed in the root directory of the project typically.
It would be great if jupyterlab-lsp support the concept of project so that it can be configured to look for configuration files of linters in the root directory of a project.

Motivation

If the concept of project is supported, users can leverage jupyterlab + jupyterlab-lsp to develop big Python project (instead of a simple Python script only).

Design Ideas

[bollwyvl]

I theoretically support this, but "project" is unfortunately one of the least precise words in computer science/engineering. The empty design heading doesn't give me a lot of insight, either.

If we want to move this forward, it would need to be filled out with some more concepts of what:

• files that would be created
• messages that would need to be sent to the language servers
• it would do in the presence of of many languages (simultaneously)
• it might look like, preferably with wireframes, links to prior art

[krassowski]

My question would be how much is this a role of jupyterlab-lsp and how much it actually belongs to jupyterlab itself.

[krassowski]

Some relevant ideas and thoughts in https://github.com/krassowski/jupyterlab-lsp/issues/642#issuecomment-877360295; LSP 3.6 introduced workspaceFolders, but some language servers are reluctant to implement it; the support is anecdotally said to be low.