[native] Navigate to the image / video modal when a user clicks on a media item
Summary:
We want to allow users to click on a media item in the gallery and navigate to either the VideoPlaybackModal or the ImageModal. The key parameter for the navigation is similar to the getMediaKey method (https://github.com/CommE2E/comm/blob/dc2f711faf30930a7c9f7f906a2a2b9f28d38bb0/native/chat/multimedia-message-utils.js#L129-L134). Here, for the thread media gallery, the key multimedia|${threadID}|${mediaInfo.index} is unique per media so when the key is pushed to the StackNavigator, there will be no existing duplicate key. We calculate the corners by checking the index of the media item relative to the gallery and the length of mediaInfos.
Depends on D6660
Test Plan:
Checked that the navigation works on both iOS and Android.
Reviewers: atul, ginsu, tomek, ashoat
Reviewed By: ashoat
Subscribers: ashoat
Differential Revision: https://phab.comm.dev/D6718