feat(experimental): keep Store internal and add Tablename method

[mfridman]

This PR updates the Store interface,

1. Keep it internal only (for now, as we settle on the final API). Still an interesting discussion here: feat(experimental): replace dialect with a state.Storage interface #608
2. Add a Tablename() string method to ensure ALL store implementations at least have it set. I don't think the goose package actually needs it, but if we're decoupling the store from the provider, we should have a single check for this in the provider constructor.
3. Break InsertOrDelete into Insert / Delete and have insert take a InsertRequest. This way we can future-proof the ability to pass additional information to Store implementations without breaking the contract.

This would potentially allow us to expand the goose table in a backwards-compatible way, #422 #288

In addition,

• Add WithStore option to support custom implementations.