Rewrite JSON schema code generator for Version 3

[diamondburned]

buttplug.io is version 3 now. I only knew of this by code-searching for the now-moved JSON schema file. This isn't really documented anywhere else.

[diamondburned]

New schema path: https://raw.githubusercontent.com/buttplugio/buttplug/refs/heads/master/crates/buttplug_core/schema/buttplug-schema.json