Non-ASCII room aliases

### Description

Element-web/desktop doesn't allow using non-ASCII characters when defining new local room alias, while matrix specifications perfectly allow for such thing.

### Steps to reproduce

- Try adding new room alias that contains ~any non-ASCII character
- See Element telling "not possible"

### Version information

- **Platform**: Both web (in-browser) and desktop, 1.7.23

### Solution:

Just accept whatever peoples write in it, as "everything" is supported in matrix specs, apart from _actual_ not allowed characters like whitespaces or so. Element even shows and joins to rooms with aliast containing `ö` or even `😀` so even that isn't generally an issue at least with rooms list. Should there be some other ineffiency in room alias handler (ad-hoc in text in chat or pill generator or whatever, those needs then fixing, would be kinda separate issue then).