Migrate to FlashList

[noumantahir]

Apparently users have reported crashes while scrolling through waves too fast, my guess is there is a performance bottleneck because of processing renderHTMLs in a long list of waves.

As suggested by @gamingumar, we can migrate FlatList to FlashList as a quick remedy to improve performance, later we can also consider optimising item renderer

• First Migrate CommentsView.tsx, that component is also used to render waves
• Migrate postComments.tsx, this component renders comment made to a post in post details screen
• Migrate PostsListContainer.tsx, use to render post feeds

[gamingumar]

#2771