Pasting call.element.io/foo into the room name box should take me to the #foo room on call.element.io

### Your use case

Current behaviour:

If I go to call.element.io and paste call.element.io/foo into the 'video call name' box then I will be taken to https://call.element.io/room/#callelementiofoo:call.ems.host rather than https://call.element.io/room/#foo:call.ems.host

This creates confusion as some users are copy-pasting a URL they have been sent, or has been included in a meeting invite, into the room name box in call.element.io rather than pasting it directly into the URL bar in their browser. This means they end up in the wrong room, and don't realise why unless they pay close attention to the URL they end up on.

Although you could argue this is user error, it's an understandable and common mistake and we should try to cater for it.

I don't know how easy it is to identify which bit of the text in the room name box is a URL, especially as in the future Element Call will run on URLs other than call.element.io, and we don't prevent users from creating room names using special characters (although we do strip them out of the URLs).

### Have you considered any alternatives?

_No response_

### Additional context

_No response_