[AppProvider] Provide a better way to override specific router configurations

[apedroferreira]

Summary

Right now, if someone using the NextAppProvider, for example, wants to override its Link component in order to add some of the Next.js transition options, they would need to create a whole custom router.

There should be a simple way to override a single property of the router, or at least the Link.

Motivation

The renderItem property for navigation page items added in #4809 provides a way to override the links, but only for those navigation items.

This option would provide a more elegant solution for this issue, at the application router level:
#4748 (comment)

Search keywords: app provider next react router navigation override custom