Remove the need to query a particular KV level, and instead use slightly different encoded keys, and use prefix based iteration. This means we can use different KV stores to give the same functionality, without needing to use hierarchical KV stores.
Don’t use the global variable ‘skip’ to decode into, as this causes a data race, when decoding keys from inside multiple different goroutines. Instead we now create a new string variable for every decode function, which will be created on the heap and ignored when the function returns.
