Add/update filtered-sum-bms benchmark

spot-launcher/node_modules/@aws-sdk/middleware-flexible-checksums/dist-es/hasHeader.js

@@ -0,0 +1,9 @@
+export const hasHeader = (header, headers) => {
+    const soughtHeader = header.toLowerCase();
+    for (const headerName of Object.keys(headers)) {
+        if (soughtHeader === headerName.toLowerCase()) {
+            return true;
+        }
+    }
+    return false;
+};