[Enhancement] Return zero/empty arrays instead of null

[asimons04]

Instead of returning null for certain keys in the API responses, consider returning 0 for numeric values or an empty array [] for values that, if populated, would normally return an array.

This would make interfacing with the API much easier for Javascript/Typescript (possibly other languages as well).

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[RikudouSage]

Isn't null generally easy to handle? Like, in TS/JS:

if (instance?.moderators) {
    // do something
}