With the addition of the IndexedDB and WebSQL adapters, which have an asynchronous api, the memory and sessionLocal adapters should also become "asynchronous" to provide api symmetry.

There will be a new "option" when creating a store called "async". it will default to false and only be valid for the memory and sessionLocal adapters.
this will allow the old adapters to work as is, or have an "async" api if this new option is true

It will then be removed in 1.4.0