Use single memory block for address list values

Currently off heap stores the values as a forward only list of separate pointers. We could instead store these in a single block of memory for each bucket. This would reduce overhead for each bucket as it would only require 1 block of memory. However every time a new entry is added or removed we would have to free the entire block of memory. This however would have the benefit of the lookup would be much more efficient when we have more entries as they are contiguous in memory.

This issue would probably benefit reads at the cost of writes possibly, but it would have to be tested with different sizes of address lookups to be sure.