* move core tests to core
* remove window
* fix up flaky tests
* test_entryfication needs a singly-threaded banking_stage
* move core benches to core
* remove unnecessary dependencies
* remove core as a member for now, test it like runtime
* stop running tests twice
* remove duplicate runs of tests in perf
* Mostly implement key-value store and add integration points
Essential key-value store functionality is implemented, needs more work to be integrated, tested, and activated.
Behind the `kvstore` feature.