Get rid of horizontal tabs

### Your use case

#### What would you like to do?

Have only one tab in Home and each space where rooms, DMs and favourites are displayed together.

#### Why would you like to do it?

For one, I dislike the Home screen with it's horizontal scrolling and redundancy (All of the categories displayed in Home can be found right next to Home as tabs).
Secondly it sometimes is confusing and therefore annoying to search for a chat and being unable to find it because you looked in the wrong tab.
And lastly I think this layout tends to waste a lot of space. For instance I only have one Favourite, but it gets a whole tab for itself, leaving a lot of space blank. That problem gets only worse when using spaces. In most spaces I don't have any People or Favourites and therefore get two empty tabs while the Home tab is basically a copy of my Rooms tab but with the rooms weirdly displayed horizontally and therefore leaving a lot of blank space.

#### How would you like to achieve it?

Get rid of the existing four tabs (not counting communities?) and merge them together in one view.
You could either
- do it like FluffyChat where favourites are pinned on top and are followed by rooms and DMs without seperation between these two or you could
- do it like Element Web/Desktop (and Android if I'm not mistaken right now) where there are the three categories favourites, DMs and rooms displayed after each other in one view with each category being collapsible (as they are alrady).

### Have you considered any alternatives?

_No response_

### Additional context

_No response_

The issue names no files, tests, or entry points. Start by locating the iOS implementation of the Home and space room-list tabs, then compare the proposed merged layouts and confirm the intended design with maintainers. Done means the existing tabs are replaced by one usable view without losing rooms, DMs, or favourites.

Written by the indexing model from the issue text.