Bring back toast removal

[ghost]

"Enforced secure chat" is now stored in the Join/Login packet. I've injected into it.
Some notes:

• Now it requires something called "profile keys" on the client, that is. launchers MUST launch clients with "profile keys" provided. Vanilla launcher does that. Others sometimes do, sometimes don't. If they don't, the toast will be shown and there's nothing you can do about it from the server-side, but it won't break stuff.
• Fabric injector has been moved a little bit back from TAIL, because Join packet is sent before TAIL in this method.

Properly fixes #50.

[pop4959]

Thanks for the PR! I was under the impression that this functionality was completely removed in the recent updates but clearly I did not look hard enough (and I have been busy lately, hence my slowness in general).

Code approved, I just ask that you make changes to the non-code portions as requested, specifically regarding the author field since this is your first PR to this project. Note that if you do plan on sticking around to help actively maintain the project, we can revisit this at a later date and I don't particularly take any issue with it then (as long as ocelotpotpie also signs off on it).

[ghost]

I've addressed your change requests @pop4959

[pop4959]

LGTM, thanks