lsp: Set workspace folder names

[0bkevin]

Objective

Fixes #60518.

Zed sends an empty name for entries in initialize.params.workspaceFolders. Language servers such as basedpyright use this field to identify workspace service instances, resulting in an unnamed instance.

Solution

Derive each workspace folder name from its URI, preferring the decoded filesystem basename. For basename-less URIs, fall back to a non-empty path, URI path segment, or the full URI.

Use the same construction for initialization parameters, dynamic workspace-folder notifications, and workspace/workspaceFolders responses so all LSP messages remain consistent.

Testing

• cargo fmt --all -- --check
• cargo test -p lsp
• cargo check -p project --all-targets --all-features
• ./script/clippy -p lsp
• ./script/clippy -p project

Reproduced with basedpyright 1.39.9 over an LSP stdio session. Before this change it logged:

Starting service instance ""

With a derived workspace folder name it logged:

Starting service instance "zed-60518-project"

Tested on macOS.

Self-Review Checklist:

• I've reviewed my own diff for quality, security, and reliability
• Unsafe blocks (if any) have justifying comments
• The content adheres to Zed's UI standards (UX/UI and icon guidelines)
• Tests cover the new/changed behavior
• Performance impact has been considered and is acceptable

Release Notes:

• Fixed language servers receiving empty workspace folder names.

[SomeoneToIgnore]

Thank you, looks quite nice.
Let's tidy up the code a bit and merge this.

[0bkevin]

Thanks! @SomeoneToIgnore all comments resolved.

[SomeoneToIgnore]

Thank you!

[0bkevin]

This should fix the Windows test failure. The test now builds the workspace URI from a native absolute temporary path, so Windows receives a drive-qualified file URI and resolves the folder name to my project, matching Unix. The fix is in 2f3cea17f3.