Adds a server running a gRPC endpoint over websockets, a client to access the server and a `ipfs-client` module that uses the gRPC client with HTTP fallback.

So far only supports `ipfs.addAll` but the idea is to implement all streaming methods over websockets instead of HTTP, to give us bidirectional streaming and errors that work in the browser.

Fixes:

Depends on:

- [ ] ipfs/js-ipfsd-ctl#561