Refactor exp logic & code cleanup

[iTruth]

just noticed that CosmicTour.cs is not the only incorrect location, Beatmaps.cs & Shop.cs contains the same issue.

[ArjixWasTaken]

🙏

[ArjixWasTaken]

I'll leave this open in case you find more places like that

[iTruth]

sigh... It seems like maxExp is not that simple, at least it should not constitute arithmetic sequence.
the reason is I obtained some data:

level	exp
1	50
8	3000
12	5000
13	5500
21	15000
25	26000
26	31000

I tried using exponential regression to find the original function, and I got the following function:
ln(y)=6.963+0.1284x
It works well in high level. but for lower levels, the deviation is significant.
to be honest, I think exp is predefined and does not constitute to any function.

by the way, I think this PR should fix the issue, I'll open another PR if I found more issue in the future. you can merge it if you want.

[ArjixWasTaken]

Oh yeah, since you are going through my code, I just want to apologize in advance for the war crimes I have commited.

pun intented :)

[ArjixWasTaken]

@iTruth here is the repository for the rust server implementation I was talking about earlier

https://github.com/ArjixWasTaken/rustaxion

currently it can only log the incoming messages, well, the main_cmd, para_cmd and such
the actual payloads are not really parsed yet

I literally started working on this today :)