Add an editable date range input to be used by the `IgcDateRangePicker`, as currently the single-input mode is non-editable. [Draft PR](https://github.com/IgniteUI/igniteui-webcomponents/pull/1733) _Estimated Delivery Sprint - Sprint X_ - [ ] Research - [ ] Specification - [ ] Component and tests implementation - [ ] API Documentation - [ ] Design implementation
