The trigger supports `throttle`, `debounce` and `takeLeading` now

Breaking change

Removed actionTypeDelimiter from App constructor, this will enforce to use / as action type delimiter

New feature

The effects() trigger map now support throttle, debounce and takeLeading

1. takeLeading example of only do fetching user once in one time

const [effects] = model.effects({}, {
  requestUser: {
    *takeLeading() {
      yield call(API.getUser)
    }
  }
})

2. debounce example of decreasing the rate of validation function call when input changes

const [effects] = model.effects({}, {
  handleInputChange: {
    *debounce(input) {
      yield call(validate, input)
    },
    ms: 500,
  }
})

3. throttle example of limiting the API calls of requesting suggestions on input changes

const [effects] = model.effects({}, {
  requestSuggestions: {
    *throttle(input) {
      yield call(API.findSuggestions, input)
    },
    ms: 1000,
  }
})