* add pss websocket api for opening a persistent connection for incoming messages on a given topic
* add pss message send api to send outgoing messages

Add ens resolver client and integrate resolver into the api package

manifest, jsonmanifest, api, node: remove parser from jsonmanifest and replace with binary marshalling

Add functionality to serve directory content

- add 'pkg/manifest'
- update 'pkg/api'

* Tag for chunks

* storage: add validating mock storage
* api: add bzzchunk api