This table purposefully does not index by partition/namespace. It's a
global view into all service names.
This table is intended to replace the current serviceListTxn watch in
intentionTopologyTxn. For cross-partition transparent proxying we need
to be able to calculate upstreams from intentions in any partition. This
means that the existing serviceListTxn function is insufficient since
it's scoped to a partition.
Moving away from that function is also beneficial because it watches the
main "services" table, so watchers will wake up when any instance is
registered or deregistered.
As part of this change the indexer will now be case insensitive by using
the lower case value. This should be safe because previously we always
had lower case strings.
This change was made out of convenience. All the other indexers use
lowercase, so we can re-use the indexFromQuery function by using
lowercase here as well.
Mark Anderson