TypeScript types: allow generic state and action

[OliverJAsh]

E.g.

const composeEnhancers = composeWithDevTools({
  stateSanitizer: (state: StateRoot): StateRoot => ({
    // …
  })
})

[OliverJAsh]

Updated to also make the action generic.

[OliverJAsh]

Issue for new repository: reduxjs/redux-devtools#1534.