User Name ALIASES for different spaces channels rooms etc

### Your use case

#### What would you like to do?
Some people may know me differently and be used to calling me by different names.
This feature is just for simple ALIASES to the same login username/profile, so that different people/rooms/spaces can see your username by specifically the alias they know you by...

Note this is ALSO a 'little' bit related to my other feature request at:
https://github.com/vector-im/element-android/issues/6053

Because the other users should also have control to be able to change the way THEY see your "displayed" ALIAS in their UI user interface. So you may have set your own alias for them, but they should/can be able to change the way an alias is "displayed" in their UI, to be able to edit their own username/alias and others' as well.

#### Why would you like to do it?
You tell me.

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

### Have you considered any alternatives?

_No response_

### Additional context

_No response_