[native] Get rid of withNavContext and connectNav
[native] Get rid of withNavContext and connectNav

Summary:
They're no longer used. Going forward, let's use hooks for data binding.

I also got rid of `navContextPropType`.

Test Plan: Flow

Reviewers: palys-swm

Reviewed By: palys-swm

Subscribers: KatPo, zrebcu411, Adrian

Differential Revision: https://phabricator.ashoat.com/D378

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