GetAuthSessionTicket implementation

[Masusder]

This is continuation of jesterret's pull request
I've added steam default of writing random data, as mentioned in #789 (comment) and changed code following @xPaw review
Full credits goes to @jesterret for this implementation

Here's example of successfull authentication using token generated by this implementation:

[xPaw]

Not really a fan of these separate UserData classes (if its always random, why does the other one even exist?)

Also put these extra classes inside of SteamAuthTicket class, not standalone.

Would love for some other users to verify that this works (commenters from the original pr?)

[xPaw]

Code wise looks fine to me, but I have not actually tested whether this works.

Would be nice if some user actually confirmed this works.

[Masusder]

Code wise looks fine to me, but I have not actually tested whether this works.

Would be nice if some user actually confirmed this works.

I unfortunately don't know anyone who could also test it. I can only mention that I've tested it on Dead by Daylight and Islands of Insight games, for both games generated ticket is accepted as valid.

[jesterret]

Thanks @Masusder for taking over the PR, I didn't have much time to look into it, and thanks @xPaw for reviewing it :)
If that would help, we could probably submit a sample project that uses the generated token to authenticate for the game?

[CLOEI]

I just tried using it in one game, and I can confirm it works.