Refactor the toggle slider in the package based on the comment

I think that `update_toggle_slider` should update only `state` and then `state` change should update slider and numeric inputs. I think there should be only one input rendered and `if (input$toggle %% 0)` should be placed in the `renderUI` - this would avoid a need to update two inputs in the same time.

_Originally posted by @gogonzo in https://github.com/insightsengineering/teal.goshawk/pull/319#discussion_r1803012866_