Maybe in system_info, basically a way to get the values of Carpet Rules.

May be useful for things like enabling or disabling a functionality (a carpet, for instance) depending on the value of a rule (the carpets rule, for instance), reacting to changes of vanilla behaviour that some rules may present, or decide whether or not to send updates based on fillUpdates.

Shouldn't throw if rule isn't found, in case it is checking for rules that may be added by extensions that aren't present.