Sharded state experiment based on call_traces stage run via integration (#1329)

* Initial work on state shards

* Fix compile errors

* Intermediate

* Implement dispatcher

* Implemented sharded reader

* No cache

* Print comms

* No prepopulation

* Print dispatcher activity

* Print more

* Print errors

* Fix dispatcher

* Remove logging

* Dispatcher to enforce initial barrier

* Don't print that much

* Turn off cache pre-seeting for state sharding

* Artificial latency, fixed number of blocks to execute

* Fix