function overrideItemIdKeyNameBeforeInitialisingDndZones(newKeyName) {
    if (activeDndZoneCount > 0) {
        throw new Error("can only override the id key before initialising any dndzone");
    }
    if (typeof newKeyName !== "string") {
        throw new Error("item id key has to be a string");
    }
    printDebug(() => ["overriding item id key name", newKeyName]);
    ITEM_ID_KEY = newKeyName;
}
Allows using another key instead of "id" in the items data. This is global and applies to all dndzones.
Has to be called when there are no rendered dndzones whatsoever.
@param {String} newKeyName
@throws {Error} if it was called when there are rendered dndzones or if it is given the wrong type (not a string)