Fix responder chain in reactViewController on macOS

[gabrieldonadel]

Summary:

I first noticed this while working on SwiftUI views for expo/expo#35078. Calling reactViewController on iOS always returns the correct view controller but on macOS, this same function will return nil for nested views.

So this PR addresses the differences in responder chain behavior between iOS and macOS when aliasing UIViewController to NSViewController. On iOS, a view's nextResponder is naturally its own UIViewController, ensuring that helper functions like reactViewController work as expected. However, on macOS, an NSView's nextResponder does not include its NSViewController by default, which causes issues when trying to retrieve the view controller directly from the responder chain.
This change ensures that traversals will properly locate the NSViewController using the superview chain, mirroring iOS behavior.

Test Plan:

Run RNTester and we've been using this same function to render SwiftUI views on macOS in expo's repo

[Saadnajmi]

However, on macOS, an NSView's nextResponder does not include its NSViewController by default, which causes issues when trying to retrieve the view controller directly from the responder chain.

I thought it did? What are you seeing as the nextResponder on your end? I'm going off of this doc fwiw https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/EventOverview/EventArchitecture/EventArchitecture.html

[gabrieldonadel]

I thought it did? What are you seeing as the nextResponder on your end? I'm going off of this doc fwiw https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/EventOverview/EventArchitecture/EventArchitecture.html

When I call reactViewController in

https://github.com/expo/expo/blob/6027354a2fd21d1c8c678780050697c1919732a0/packages/expo-modules-core/ios/Core/Views/SwiftUI/SwiftUIHostingView.swift#L165-L175

this internally will call nextResponder and that is nil

[Saadnajmi]

/azp run

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Azure Pipelines successfully started running 1 pipeline(s).

[Saadnajmi]

/azp run

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Azure Pipelines successfully started running 1 pipeline(s).

[Saadnajmi]

@gabrieldonadel If you'd like this on 0.76 or 0.77, feel free to make a backport PR, and I'll make sure we get a published patch release with it. Otherwise this will land with RNM 0.78