Add missing extension key field to mutation result (#522)

Regression introduced with c8747d6

Author: schroda

src/lib/graphql/mutations/ExtensionMutation.ts

@@ -27,6 +27,7 @@ export const UPDATE_EXTENSION = gql`
         updateExtension(input: $input) {
             clientMutationId
             extension {
+                pkgName
                 apkName
                 versionName
                 versionCode
@@ -43,6 +44,7 @@ export const UPDATE_EXTENSIONS = gql`
         updateExtensions(input: $input) {
             clientMutationId
             extensions {
+                pkgName
                 apkName
                 versionName
                 versionCode