GitLab

add the ability to send extensions when creating requests

To reduce future import cycles, and expose more types properly, move the root package to an
interface/types file and move the main implementation into /impl. This also exposes an interface
other implementers can replace.

Adds callbacks to manage connections, also removes network receiver methods from public graphsync
interface, and updates libp2p to handle go-libp2p-core refactor

Updates IPLD Bridge to use latest go-ipld-prime and runs and actual round trip test using GraphSync,
go-ipld-prime, and real selectors

Move ResponseProgress to the types package and extract some testing functions to testutil

Make the request manager actually inject responses from the network, and perform a selector
verification

Convert GraphSyncRequest and GraphSyncResponse to structs, track by value, pass directly into add
methods on GraphSyncMessage

Handle failed request status codes from server and pass on errors

Add a channel of asynchronous errors instead of only an initial synchronous one

Create a manager for outgoing requests