Convert to BlockNote, Image support, Video Support, tamagui theme, white and black theme

Huge release! Added the following:

1. Used BlockNote for the editor which allows
   for notion-like editor. This includes
   dragging blocks, SideMenuPositioner, a
   FormatToolPositioner, and many custom
   nodes.
2. Theme Switching between light and dark
   mode
3. Image and Video support
4. Hybrid Search
5. Re-added SimilarSideBarComponent