fix(click controls): don't collapse on all clicks

Closes #28 

Moves and improves the control click logic out of the conversation component so we can manage the global state of all conversations.

- If the currently active conversation's control is clicked the conversation closes.
- If conversation A is open and the user clicks conversation B's control, A closes and B opens.
- If the active conversation itself is clicked, it doesn't close
- If anywhere else on the document is clicked, the conversation will close.