Remember scroll position in chat rooms

### Your use case

#### What would you like to do?
When leaving the room view or closing the app and going back the scroll position should stay relatively the same.

#### Why would you like to do it?
When searching for older message user should not fear accidental press of a back button or checking other room for a moment.
This would be especially useful with the fast nature of Element X.

#### How would you like to achieve it?
Saving information about the latest message visible on screen and load the fragment of conversation containing it when opening up the room.

### Have you considered any alternatives?

_No response_

### Additional context

One of the apps which also implements this feature is Telegram.

### Are you willing to provide a PR?

No