Include sender keys in SignalProtocolStore zones

ts/util/Zone.ts

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 export type ZoneOptions = {
+  readonly pendingSenderKeys?: boolean;
   readonly pendingSessions?: boolean;
   readonly pendingUnprocessed?: boolean;
 };
@@ -12,6 +13,10 @@ export class Zone {
     private readonly options: ZoneOptions = {}
   ) {}
 
+  public supportsPendingSenderKeys(): boolean {
+    return this.options.pendingSenderKeys === true;
+  }
+
   public supportsPendingSessions(): boolean {
     return this.options.pendingSessions === true;
   }