Make TypingView part of the timeline so it doesn't take extra space above the composer

[jmartinesp]

Your use case

What would you like to do?

Move the ' is typing...' notification from the top of the message composer to the timeline.

Why would you like to do it?

Right now, it's always there and takes extra space, making the composer look larger than it actually is, as they also share the same background color.

How would you like to achieve it?

Creating an extra item at the end of the timeline with the TypingView, making it only visible when needed.

Have you considered any alternatives?

I though about making a view that is displayed over the bottom of the timeline, but that would probably be annoying to users as it would hide what's in the timeline.

There could also be a view that appeared from below the timeline and resized it, but it would probably be annoying too.

Additional context

No response

Are you willing to provide a PR?

Yes