perf: list updates regressions and animated optimization

[isekovanic]

🎯 Goal

This PR updates addresses some performance degradations which got introduced with V9 and the redesign.

Most notably:

• It moves the context menu shared values on a higher level and just uses them downstream (creating a lot of shared values is not free because of the amount of native bindings they imply)
• It fixes an issue with our animated version of our MessageList, since any animated component (even ones done through createAnimatedComponent) have a sideeffect of changing the identity of the style property on every render. This is not something we can bypass, but the best we can do here is make sure that the list is memoized and the style only changes together with the data prop. This is still a tiny bit slower than a normal FlatList, however it's a good trade-off; especially since we provide a way to turn it off.
• It makes sure that Portals are not mounted even when they aren't needed (they should default to normal empty <View /> holders which will likely get collapsed when the shadow DOM gets reconciled, but it still avoids setting up native view bindings even if this is supposed to be cheap
• In order to preserve renderItem being stable, we introduce a precomputation of previous and next items in the list which makes sure to preserve object identity in order for us to be able to freely use those items in the list. This improves things significantly (by around 20ms per rerender specifically on very low end devices) while still keeping the stability.

🛠 Implementation details

🎨 UI Changes

iOS

Before	After

Android

Before	After

🧪 Testing

☑️ Checklist

• I have signed the Stream CLA (required)
• PR targets the develop branch
• Documentation is updated
• New code is tested in main example apps, including all possible scenarios
  • SampleApp iOS and Android
  • Expo iOS and Android

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
js_bundle_size	420 KB	420 KB	+598 B	🔴