Function apply_inverted_lookup 

fn apply_inverted_lookup<K, V>(
    map: &mut BTreeMap<K, V>,
    key: &K,
    value: V,
    diff: StateDiff,
)
where
    K: Ord + Clone + Debug,
    V: PartialEq + Debug,

Helper method to updated inverted lookup maps. The keys are generally names and the values are generally IDs.

Importantly, when retracting it’s expected that the existing value will match value exactly.