feat(game/five): save pure level - #4219

Goal of this PR

This PR saves players time when connecting to servers with sv_pureLevel > 0. Currently, joining such servers requires a game restart every time; this change eliminates that need. Additionally, if a player is running a higher pure level than the server requires, they are asked whether they want to switch to the server's level or keep their current one.

I'm opening new PR because my previous one was forgotten. I believe this change should be implemented as it will make things much easier for everyone.

How is this PR achieving the goal

Save pure level to CitizenFX.ini to avoid game restart when joining pure servers.

This PR applies to the following area(s)

FiveM

Successfully tested on

Platforms: Windows

Checklist

• Code compiles and has been tested successfully.
• Code explains itself well and/or is documented.
• My commit message explains what the changes do and what they are for.
• No extra compilation warnings are added by these changes.