fix: Select conversation issue on iOS

[avivdim]

On Android, the Zendesk messaging view worked as expected because it was displayed as part of the regular screen flow. On iOS, using rootController.show(viewController, sender: self) pushed the Zendesk view onto the navigation stack. However, the Zendesk view was just a single screen, and there was no deeper navigation (i.e., tapping on a conversation to open a detailed view), so the interaction issues didn't appear. After the update that introduced multi-conversation support, where tapping on a conversation opens a deeper screen, the previous approach caused issues because the Zendesk view was not properly integrated into the app's navigation stack. This prevented the deeper navigation from functioning correctly (e.g., tapping on a conversation didn't lead to a new screen).

Solution:

1. We checked if a UINavigationController was available in the app.
2. If a UINavigationController was present, we pushed the Zendesk view onto the navigation stack, allowing for proper
   navigation (e.g., tapping on a conversation now pushes a new screen).
3. If no UINavigationController was found, we ensured the Zendesk view was presented fullscreen, but still part of the normal navigation context.

This fix resolves the interaction issue by ensuring the Zendesk view is correctly integrated into the app’s navigation stack, enabling the deeper screen navigation introduced by the multi-conversation update and providing a smooth user experience.

[leegeunhyeok]

LGTM 👍

I'll test these changes on React Native 0.71 and 0.77 this week, and I'll approve them after testing.

refs #75

[leegeunhyeok]

Before	After
Screen.Recording.2025-01-11.at.15.10.08.mov	Screen.Recording.2025-01-11.at.15.17.47.mov

[leegeunhyeok]

closes #59