Implementing discussion bubbles in Element

[ghost]

The vast majority of consumer messaging applications such as Signal, Telegram or WhtasApp have this functionality.
It's a feature that the people around me are asking for a lot; speech bubbles make conversations "warmer".
And this aspect, I think, is very important to take into account if Element wants to appeal to a large audience !
Without bubbles, Element is a little bit repulsive to the labda user who finds bubble-free conversions too "professional" or "geeky"...

[duncanturk]

I think it's a duplicate of #979

[kittykat]

Closing because this is a duplicate of #979