Fix keyspace strategy options to preserve key-value ordering by
switching to std::map. We need this to be able to store the map in
database as JSON because unordered maps can cause the schema merging
code to attempt a keyspace update, which we don't support, even though
the values did not change.
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
d088cb8181