Improve keyboard shortcuts toggling space panel, room list, right panel

### Your use case

#### What would you like to do?
current shortcuts as far as i can see are

i would like to make them more logical and add a toggle for the room list

#### Why would you like to do it?
easier to remember, additional feature

#### How would you like to achieve it?
what is Ctrl+Shift+D based on? D seems unrelated to "Space". it is also a big 3 keys combo out of nowhere.

suggestion:
1. keep right panel with Ctrl+. #12248
2. add room list with Ctrl+, (the key left of .)
3. update space panel to Ctrl+Shift+, where Shift = "even further left". Also because Ctrl+M in my browser is taken.

### Have you considered any alternatives?

an alternative with 2 or 3 keys next to each other

### Additional context

#3232