chore(config-resolver): add optional signing region/service in RegionHash

Author: trivikr

packages/config-resolver/src/regionInfo/PartitionHash.ts

@@ -4,5 +4,12 @@
  * and the hostname to be used for the partition.
  */
 export type PartitionHash = {
-  [key: string]: { regions: string[]; regionRegex: string; hostname?: string; endpoint?: string };
+  [key: string]: {
+    regions: string[];
+    regionRegex: string;
+    hostname?: string;
+    endpoint?: string;
+    signingRegion?: string;
+    signingService?: string;
+  };
 };