Limit typing notifications timeline jumps

[gaelledel]

This was suggested by @ara4n
In order to limit typing notifications to move the timeline constantly when someone stops/starts typing, it was suggested to keep the gap used for the typing notification on up until:
1/The user explicitly moves up/down the timeline
2/The user navigates out of the room chat

At this point, when these actions are performed, the gap should not be displayed.

[nadonomy]

@gaelledel @gileluard to clarify— would this mean:

1. The timeline animates up to make space for typing notifications
2. Once a message arrives, it's cleared and a message is displayed in place, with no gap
3. If the typing notification is dismissed, we'd be left with whitespace in the timeline where the typing notification was

?

If so, then the actions in this issue would be when we'd clear the whitespace? Could we animate the timeline back into place?

[gileluard]

@gaelledel I assign this ticket to you for the moment. You can assign me this ticket once the design defined.

[gaelledel]

1. The timeline animates up to make space for typing notifications --> Yes
2. Once a message arrives, it's cleared and a message is displayed in place, with no gap --> Yes
   If the typing notification is dismissed, we'd be left with whitespace in the timeline where the typing notification was
   ? --> Yes

If so, then the actions in this issue would be when we'd clear the whitespace? Could we animate the timeline back into place? --> The Gap in the timeline should be removed as soon as:
1 - Users navigate outside the chatroom (e.g: pressing on back button)
2 - Users scroll the timeline upwards. When users return to the bottom of the timeline, no gap should be visible. They can do so by manually scrolling back down or by pressing the Scroll down button.