fix: pipe metadata along (#1178)

* pipe metadata along

* Arrange imports back to where they were

* revert some automatic imports

* revert automatic import

* report metadata when it doesn’t exist yet

* should include metadata in result

* Remove only

* Removed setting metadata that is no longer used

* Add an assert fail

* Better check for metadata

* use bind instead

* revert changes for exposing metadata directly

* change stream emit metadata back

src/index.ts

@@ -863,6 +863,7 @@ export class Bigtable {
         gaxStream = requestFn!();
         gaxStream
           .on('error', stream.destroy.bind(stream))
+          .on('metadata', stream.emit.bind(stream, 'metadata'))
           .on('request', stream.emit.bind(stream, 'request'))
           .pipe(stream);
       });
@@ -879,6 +880,9 @@ export class Bigtable {
           .on('error', (err: Error) => {
             stream.destroy(err);
           })
+          .on('metadata', metadata => {
+            stream.emit('metadata', metadata);
+          })
           .on('response', response => {
             stream.emit('response', response);
           })