Expose refresh projects tree (#18890)

* refresh project tree after apply schema compare to project

* clarify comment

extensions/data-workspace/src/services/workspaceService.ts

@@ -168,6 +168,13 @@ export class WorkspaceService implements IWorkspaceService {
 		}
 	}
 
+	/**
+	 * Fire event to refresh projects tree
+	 */
+	public refreshProjectsTree(): void {
+		this._onDidWorkspaceProjectsChange.fire();
+	}
+
 	/**
 	 * Returns an array of all the supported projects in the folder
 	 * @param folder folder to look look for projects