* Fix Explain queries
* Add Vertex/Edge accessor support for properties
* Fix projections
* Fix expansions to fetch destination vertex properties
* Fix improper use of ShardMap on bolt and replaced it with the ShardRequestManager
* Add NameToId mappers on ShardRequestManager
* Add e2e tests for operators
* Fix OPTIONAL MATCH
Add testing capabilities similar to what existed before on the older
architecture. With this test specifically, test if we can create
vertices and return them with ScanAll. There is a hard-coded 3s wait in
the test which is needed because the MachineManager need this time to
initialize itself.
