In React Navigation, the screen options can be specified statically. If you need to configure any options based on props and state of the component, or want to update state and props based on some action such as tab press, you need to do it in a hacky way by changing params. it's way more complicated than it needs to be. It also breaks when used with HOCs which don't hoist static props, a common source of confusion.
This PR adds a `setOptions` API to be able to update options directly without going through params.
