WIP: initial prototype

- Standardized event emitters
- Refactored transport.request to have a better handling of the state
- Added sniff event
- Improved abort handling

index.d.ts

@@ -468,6 +468,7 @@ declare const events: {
     RESPONSE: string;
     REQUEST: string;
     ERROR: string;
+    SNIFF: string;
 };
 
 export { Client, Transport, ConnectionPool, Connection, Serializer, events, ApiResponse };