Update constants.ts to add bsc for smart transactions (#483)

Author: antonydenyer

src/constants.ts

@@ -7,6 +7,7 @@ type SentinelApiBaseUrlMap = {
 // The map with types applied
 export const SENTINEL_API_BASE_URL_MAP: SentinelApiBaseUrlMap = {
   1: 'https://tx-sentinel-ethereum-mainnet.api.cx.metamask.io',
+  56: 'https://tx-sentinel-bsc-mainnet.api.cx.metamask.io',
   11155111: 'https://tx-sentinel-ethereum-sepolia.api.cx.metamask.io',
 };