catch corrupted files

[RacoonDog]

Type of change

• Bug fix
• New feature

Description

Here's a fun fact! Did you know the NbtIo.read() javadoc is wrong?

Yep! They actually catch IOException's and rethrow them as CrashException's, which are not a subclass of IOException and not stated in the javadoc.
Anyways this PR catches those and prevents it from crashing the game, as well as creating a backup before overwriting the erroring settings.
Note: I kept the IOException catch and explicitly didn't make it create a backup, as that would indicate something might be wrong with the backup process, or IO operations. It will still allow the game to run, it will just overwrite the settings.

How Has This Been Tested?

Checklist:

• My code follows the style guidelines of this project.
• I have added comments to my code in more complex areas.
• I have tested the code in both development and production environments.