Add `header` and related properties support for BottomNavigation in React Native Paper

[Falicitas]

Firstly, I would like to thank the React Native Paper team for excellent work.

I noticed that in the current version of React Native Paper’s BottomNavigation, there is no header and related properties like those available in React Navigation’s BottomNavigation. In complex nesting scenarios, having a header in BottomNavigation would enable more flexible layout options.

I believe that incorporating this feature could significantly enhance the utility of BottomNavigation, making it more versatile and compatible with a variety of layouts. Therefore, I am raising this issue to request this enhancement.

Thank you for your attention and hard work!

[Falicitas]

I found BottomNavigation.Bar, which works with @react-navigation/bottom-tabs's BottomTabNavigator, allowing the use of an MD3-styled BottomTab along with a header.