Merge pull request #5160 from BitGo/BTC-1582

chore(sdk-core): add feeMultiplier to sendmany params

Author: davidkaplanbitgo

modules/sdk-core/src/bitgo/wallet/iWallet.ts

@@ -628,6 +628,7 @@ export interface SendManyOptions extends PrebuildAndSignTransactionOptions {
   }[];
   numBlocks?: number;
   feeRate?: number;
+  feeMultiplier?: number;
   maxFeeRate?: number;
   minConfirms?: number;
   enforceMinConfirmsForChange?: boolean;