provide original store slice state before in went through Tesler reducer as a reducer argument to allow overriding built-in behavior

[Dergash]

At the moment there is no obvious way to override Tesler reducer reacting to built-in action:

tesler-ui/src/interfaces/store.ts

Lines 24 to 26 in 668d0d2

	export interface ClientReducer<ReducerState, ClientActions> {
	initialState: ReducerState
	override?: boolean

ClientReducer type provides override flag and it is in fact respected, but it is conceptionally flawed in a way that most projects treat slice reducer as a single function with a giant switch inside, so this flag will replace reducers for the entire store slice.
This has absolutely no usage in real life and will be removed 2.0.0

Two other currently available options:

1. Use custom action type - not always convinient as Tesler action might be dispatched deeply from Tesler epic or component so overriding reducer for one action will require a large chunk of code from client application developer; not vialable
2. Revert changes from Tesler reducer manually in client side reducer; this is how it's currently handled in most projects. Some disadvantages: developer has to look into Tesler implementation to understand what to revert; changes in Tesler reducer will break client reducer; addional code.

This PR provides client application reducer with additional argument: originalState, that contains the state of Redux store slice before it went through Tesler reducer:

export function session(
  state = initialState,
  action: AnyAction,
  store: Store,
  originalState: Session
): Session {
  switch (action.type) {
    case types.loginDone: {
      // implement custom logic and return based on `originalState` instead of `state`
      return { ...originalState }
    }
    // ...
  }
}