Webhost: add file downloads to the room api endpoint

[alwaysintreble]

What is this fixing or adding?

title. also removes the unused ds3 download link

How was this tested?

checked that the links at the api endpoint matches those that get generated on the room page.

If this makes graphical changes, please attach screenshots.

[qwint]

locally hosted on 3.11 and 3.8 using a seed that has a SMW patch file
confirmed that with the roomId and knowing your slot number you can find the download link for your relevant game (compared with the one in the room UI) in /api/room_status/{roomId}

I'm not sure how a game is supposed to get that roomId to make the api useful, but i'm assuming it's related to #2779

[alwaysintreble]

I'm not sure how a game is supposed to get that roomId to make the api useful, but i'm assuming it's related to #2779

The room suuid is in the url queries in #2779. It probably makes more sense to just add that specific query here, but the passed url already had to be modified in that PR so I just added it instead of creating merge conflicts.

[qwint]

ah yea, double checked and it's passed in plain as day
i forgot about that because my last slew of testing on #2779 was manually writing the urls into launcher.py parameters to make sure my game was configured right, whoops