api!(deltachat-jsonrpc): use kind as a tag for all union types

deltachat-rpc-client/examples/echobot_advanced.py

@@ -14,9 +14,9 @@ hooks = events.HookCollection()
 
 @hooks.on(events.RawEvent)
 async def log_event(event):
-    if event.type == EventType.INFO:
+    if event.kind == EventType.INFO:
         logging.info(event.msg)
-    elif event.type == EventType.WARNING:
+    elif event.kind == EventType.WARNING:
         logging.warning(event.msg)