message type note defined when generating from cursor.

[Gabriel-Gebril]

In lollms_generation_events.py located in lollms-webui\lollms_core\lollms\server\events ", MSG_OPERATION_TYPE" must be appended on line 18 for the playground to generate text from cursor position. I also removed type checking on message_type (which might be unsafe but was required to get the playground to work).