- Remove the prev. React effect for managing pattern block editing modes
- Implement higher order reducer in the block editor store ... it:
    - Tracks the clientIds of pattern blocks.
    - Uses the pattern block clientIds to manage block editing modes
      for pattern blocks and their inner blocks.
    - Updates both on any actions that change block lists.

This reverts commit e1d6ca4.

It doesn't really work, since reducer won't have access to `state.blocks.tree`.

…educer. Add special handling for only adding pattern block itself as content only when not in zoomed out or nav mode

…en synced pattern overrides or when write mode is active