Show inline previews for LSP document colors (#32816)

https://github.com/user-attachments/assets/ad0fa304-e4fb-4598-877d-c02141f35d6f

Closes https://github.com/zed-industries/zed/issues/4678

Also adds the code to support `textDocument/colorPresentation`
counterpart that serves as a resolve mechanism for the document colors.
The resolve itself is not run though, and the editor does not
accommodate color presentations in the editor yet — until a well
described use case is provided.

Use `lsp_document_colors` editor settings to alter the presentation and
turn the feature off.

Release Notes:

- Start showing inline previews for LSP document colors

crates/lsp/src/lsp.rs

@@ -804,6 +804,9 @@ impl LanguageServer {
                         related_document_support: Some(true),
                     })
                     .filter(|_| pull_diagnostics),
+                    color_provider: Some(DocumentColorClientCapabilities {
+                        dynamic_registration: Some(false),
+                    }),
                     ..TextDocumentClientCapabilities::default()
                 }),
                 experimental: Some(json!({