IPFS Fileshare implementation

[smartin015]

See #2 for extra details.

IPFS is a robust protocol for filesharing which includes garbage collection and file publishing. Using DNSLink, we can also maintain a distributed registry of WAN queues in the future.

• [x] IPFS Fileshare proof-of-concept (post and fetch a file)
• [x] Convert Fileshare implementation to use IPFS
• [x] Convert unit tests for IPFS implementation

[smartin015]

Bonus optimization - include a list of IPFS swarm connections in the queue registry entry for faster file fetching (see https://stackoverflow.com/questions/55575918/pubsub-between-two-nodes-in-ipfs)

[smartin015]

This is done from #5