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/proto/src/proto.rs

@@ -221,6 +221,10 @@ messages!(
     (ResolveCompletionDocumentationResponse, Background),
     (ResolveInlayHint, Background),
     (ResolveInlayHintResponse, Background),
+    (GetDocumentColor, Background),
+    (GetDocumentColorResponse, Background),
+    (GetColorPresentation, Background),
+    (GetColorPresentationResponse, Background),
     (RefreshCodeLens, Background),
     (GetCodeLens, Background),
     (GetCodeLensResponse, Background),
@@ -400,6 +404,8 @@ request_messages!(
         ResolveCompletionDocumentationResponse
     ),
     (ResolveInlayHint, ResolveInlayHintResponse),
+    (GetDocumentColor, GetDocumentColorResponse),
+    (GetColorPresentation, GetColorPresentationResponse),
     (RespondToChannelInvite, Ack),
     (RespondToContactRequest, Ack),
     (SaveBuffer, BufferSaved),
@@ -487,9 +493,11 @@ entity_messages!(
     BufferSaved,
     CloseBuffer,
     Commit,
+    GetColorPresentation,
     CopyProjectEntry,
     CreateBufferForPeer,
     CreateProjectEntry,
+    GetDocumentColor,
     DeleteProjectEntry,
     ExpandProjectEntry,
     ExpandAllForProjectEntry,