admin feature: allow public to submit bracket urls, admin approve/tag

[VestboyMyst]

i think this was the original idea years ago and its becoming more important as more events are made

basically add some tab where there is a field for un-signed in users to submit missing URLS (challonge/smashgg) . first system checks if they exist already, if not they add them to some admin dashboard where we can go in and approve/delete them.

not a high priority task but will be welcome eventually. once this is added we can play with the idea of having others submit player merges and having admins approve that too

[BrandonCookeDev]

I was thinking about this recently. The only thing I'd be sort of on the fence about is that this could give someone an easy ability to DOS the server unless some conditional logic is written to block an IP after x submissions.
That, however, wouldn't prevent a DDOS attempt.

[jschnei]

there's already pretty easy ways to DOS us, I don't think we'd need to worry about this specifically.