Navigation: Make createNavigation and convertClassic part of Core Data

[scruffian]

Raised in #52573:

What I don't like this the way we're having to pass in the createNavigation handler from another hook.

What this all points to is that the following should be part of Core Data (or #52134):

createNavigation
convertClassic

By moving these to global state we can safety make calls and know that the same resolution state will be applicable to all >instances. This will avoid future bugs and avoid us playing callback tennis across various hooks.

As these are Core-like actions I think this is more than acceptable.