Fix the reasoner response processing part

[songmeo]

Currently, once the reasoner responses after a tool call, the conversation assumes that it's the result of the tool call. However, sometimes the reasoner is just giving task updates, which is the case for most long tasks. The conversation needs to understand that it's not function call output and it should continue to wait.

[songmeo]

another issue: sending a new message while there is an unfinished function call resulting in "no function call output" error.

[songmeo]

closes with #47

[songmeo]

The model now rejects new task and only runs it after the current task completes.