Pin Origin messaging content on Protocol Labs IPFS cluster

[franckc]

Protocol Labs offered to pin our content.

We'll need to send them IPFS hashes of our messaging data for pinning.
They have a REST API we can call to send them the pins. It is a Go client but hopefully we can implement a simple JS version of it.

We could either

• have the OrbitDB server do the pinning
• have a separate daemon (the same that will do the pinning for Listing content) send the messaging pins.

@crazybuster thinks it is easier to go for the former.

[franckc]

CC @tomlinton