Add CopilotRelated command (#59963)

src/server/protocol.ts

@@ -202,6 +202,7 @@ export const enum CommandTypes {
     ProvideInlayHints = "provideInlayHints",
     WatchChange = "watchChange",
     MapCode = "mapCode",
+    CopilotRelated = "copilotRelated",
 }
 
 /**
@@ -2406,6 +2407,18 @@ export interface MapCodeResponse extends Response {
     body: readonly FileCodeEdits[];
 }
 
+export interface CopilotRelatedRequest extends FileRequest {
+    command: CommandTypes.CopilotRelated;
+    arguments: FileRequestArgs;
+}
+
+export interface CopilotRelatedItems {
+    relatedFiles: readonly string[];
+}
+
+export interface CopilotRelatedResponse extends Response {
+    body: CopilotRelatedItems;
+}
 /**
  * Synchronous request for semantic diagnostics of one file.
  */