chore: cleanup

[saadndm]

Description

All the changes here are to make ornithe port easier, there are no functional changes

• Removed BlurHandler, it was a no-op after 58770a3
• Reset some wrong stonecutter comments

OneConfig.java:

• Add missing //? if wwaypoints_compat guard

stonecutter.gradle.kts:

• Use string replacements instead of regex so that stonecutter can handle them transitively, the replacements end with \n so that they dont match java imports like before
• Removed identifier replacement, only BlurHandler used it

mixins.oneconfigv1.json:

• Added mixinextras minversion so that https://github.com/LlamaLad7/MixinExtras/wiki/Expressions-Setup can be used

Checklist

• I made a clear description of what was changed
• I stated why these changes were necessary
• I updated documentation or said what needs to be updated
• I made sure these changes are backwards compatible
• This pull request is for one feature/bug fix