[Story] Auto-fill room's address (alias) in case of a public room

[mxandreas]

Description

• As a user who has chosen to create a public room
• I want the room address to be auto-filled for me
• So that I would be less puzzled about what's a room address and what should I type in there

Conditions:

• The algorithm to auto-fill the should derive the address from the room's name (as it gets entered by the user):
  • By removing symbols that are not allowed;
  • Except when the not allowed symbol is a whitespace - then replace it with a dash (-)
• The auto-filling is done live (e.g. as user is typing in the room name):
  • Should user make manual edits to the room address, the auto-filling should pause (e.g. not make updates to the address even user edits the room name).
  • Should the user completely erase the room name, the auto-filling should resume.
• It is not expected the algorithm to solve potential collisions with already existing addresses.

See https://github.com/element-hq/element-meta/issues/2585 for which symbols are allowed and which not.

Acceptance criteria

• The user can see the address to be auto-filled as they enter or change the room's name.
• When user changes the address manually, and then goes and changes again the room name, the address is no longer updated.

Size estimate

None

Dependencies

• None

Out of scope

• Nothing

Open questions

### Questions
- [x] The details of the algorithm need to be confirmed. The current proposal is based on observing what EW does when creating a public space. We should confirm the exact algorithm from the code and see if has any known problems.

Subtasks

### Android
- [ ] https://github.com/element-hq/element-x-android/issues/3867

### iOS

### Rust

### Other

[mxandreas]

I made 2 updates regarding auto-filling address:

• Clarified that auto-filling is done live.
• That auto-filling should resume when user completely erases the room name.