[language extensions] Use extension-api typedefs

This CL removes the remaining duplicates of the langauge extension api
type declarations, and uses the extension-api in their place.

Drive-by: Add an enumerators field to the API.

Bug: none
Change-Id: Ic71871aa0364eb715fa90ab5cc1becf5a43cb9e9
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/3045353
Reviewed-by: Tim van der Lippe <tvanderlippe@chromium.org>
Commit-Queue: Philip Pfaffe <pfaffe@chromium.org>
diff --git a/extension-api/ExtensionAPI.d.ts b/extension-api/ExtensionAPI.d.ts
index 409d841..27b1576 100644
--- a/extension-api/ExtensionAPI.d.ts
+++ b/extension-api/ExtensionAPI.d.ts
@@ -134,6 +134,12 @@
       name: string;
     }
 
+    export type Enumerator = {
+      name: string,
+      value: unknown,
+      typeId: unknown,
+    };
+
     export interface FieldInfo {
       name?: string;
       offset: number;
@@ -144,6 +150,7 @@
       typeNames: string[];
       typeId: unknown;
       members: FieldInfo[];
+      enumerators?: Enumerator[];
       alignment: number;
       arraySize: number;
       size: number;