feat(witchery): add witchery vampire support for sleep percentage.

[hinyb]

fixes GTNewHorizons/GT-New-Horizons-Modpack#22953

[Lyfts]

This would be much more maintainable if you worked mod support into the already existing class for sleep percentage https://github.com/GTNewHorizons/ServerUtilities/blob/master/src/mixins/java/serverutils/mixins/early/minecraft/MixinWorldServer_SleepPercentage when witchery is loaded.

Duplicating all of the code for the same feature into a separate class only complicates future changes.

[hinyb]

This would be much more maintainable if you worked mod support into the already existing class for sleep percentage https://github.com/GTNewHorizons/ServerUtilities/blob/master/src/mixins/java/serverutils/mixins/early/minecraft/MixinWorldServer_SleepPercentage when witchery is loaded.

Duplicating all of the code for the same feature into a separate class only complicates future changes.

I originally wanted to use static dispatch for some reason, but you are right, it's unnecessary.
Finished, thanks for the feedback.

[Lyfts]

Code looks fine. Only tested briefly on my private server, but seems to work fine.