feat(sdk): addStore() accepts pinnedPubkeyPem

Regenerate Dart bindings for AddStoreRequest.pinned_pubkey_pem and
thread it through HubClient.addStore so clients can pin a per-store
publisher key.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

lib/src/hub_client.dart

@@ -669,6 +669,7 @@ class HubClient {
     String bearerEnv = '',
     String basicUser = '',
     String basicPasswordEnv = '',
+    String pinnedPubkeyPem = '',
   }) {
     return _admin.addStore(pb.AddStoreRequest(
       name: name,
@@ -676,6 +677,7 @@ class HubClient {
       bearerEnv: bearerEnv,
       basicUser: basicUser,
       basicPasswordEnv: basicPasswordEnv,
+      pinnedPubkeyPem: pinnedPubkeyPem,
     ));
   }