Improve the type of the `selectors` argument to `createStoreModule` to
link it to the type of the initial state returned by the `initialState`
argument. This enables TS to check/infer that the first argument to
these functions should be of the same type that `initialState` returns.

In the process it was necessary to remove the `ModuleConfig` type and
declare the type of `createStoreModule`'s `config` argument inline.
This works around a TypeScript limitation [1]:

```
@template State
@template {SelectorMap<State>} Selectors // Unexpected error
...
@typedef ModuleConfig
```

But this works:

``
@template State
@template {SelectorMap<State>} Selectors // OK
...
function createStoreModule(...) { ... }
```

[1] https://github.com/microsoft/TypeScript/issues/43403