[Backport 8.1] Export SniffingTransport (#1653)

Co-authored-by: Tomas Della Vedova <delvedor@users.noreply.github.com>

index.d.ts

@@ -18,7 +18,8 @@
  */
 
 import Client from './lib/client'
+import SniffingTransport from './lib/sniffingTransport'
 
 export * from '@elastic/transport'
-export { Client }
+export { Client, SniffingTransport }
 export type { ClientOptions, NodeOptions } from './lib/client'

index.js

@@ -35,9 +35,11 @@ const {
 } = require('@elastic/transport')
 
 const { default: Client } = require('./lib/client')
+const { default: SniffingTransport } = require('./lib/sniffingTransport')
 
 module.exports = {
   Client,
+  SniffingTransport,
   Diagnostic,
   Transport,
   WeightedConnectionPool,