runfix: Avoid sending typing stop when user has not typed at all

[atomrc]

Description

We need to keep track of whether the user has typed or not in a conversation to avoid sending too many typing stop events.
This will also prevent sending typing stop messages to conversation that do not exist anymore.

Checklist

• PR has been self reviewed by the author;
• Hard-to-understand areas of the code have been commented;
• If it is a core feature, unit tests have been added;