* Expand state provider fakes
- default null initial value for fake states
- Easier mocking of key definitions through just the use of key names
- allows for not exporting KeyDefinition as long as the key doesn't collide
- mock of fake state provider to verify `get` calls
- `nextMock` for use of the fn mock matchers on emissions of `state$`
- `FakeAccountService` which allows for easy initialization and working with account switching
* Small bug fix for cache key collision on key definitions unique by only storage location
* Fix initial value for test
