Disclaimer: this mainly concerns Scarb-based projects, as loading cairo_project.toml-based project is cheap.

Problem: currently, we load project model on every didOpen cairo file notification, even when the file that was opened was in a Scarb workspace we already loaded into our project model. This makes us call scarb metadata more than needed, which is hightly inefficient.

Solution: keep track of workspaces we loaded into our project model. If a config file corresponding to the file that was opened is Scarb.toml and it belongs to a known workspace, then don't reload the project model.

Concern about detached files: this logic will reinforce ignoring detached files on the server side.