feat(pub): update publication pull
- Implemented GetNewestPublication to retrieve the most recently published leaflet note.
- Added DeleteAllLeafletNotes to remove all leaflet notes
- enhance ATProtoService with CBOR to JSON conversion
- Updated PullDocuments to handle CBOR decoding and JSON conversion.
- Integrated viewport for viewing content in data_list.go.
- create PublicationView for displaying notes as markdown