This change amends it so we use a static service to keep track of
the typing presence.
It correct various edge cases the initial implementation had
- Faster close messages
- When composing on topic 1 and viewing topic 2 we had incorrect
presence
- Changing a running composer to reply as new topic or reply to a
differet topic would not correctly shift presence
Authored by tgxworld, with contributions by sam
Before this commit, the presence state of users were stored on the
server side and any updates to the state meant we had to publish the
entire state to the clients. Also, the way the state of users were
stored on the server side meant we didn't have a way to differentiate
between replying users and whispering users.
In this redesign, we decided to move the tracking of users state to the client
side and have the server publish client events instead. As a result of
this change, we're able to remove the number of opened connections
needed to track presence and also reduce the payload that is sent for
each event.
At the same time, we've also improved on the restrictions when publishing message_bus messages. Users that
do not have permission to see certain events will not receive messages
for those events.
