GitLab

Per https://github.com/ipld/specs/pull/205, metadata is now an extension, and further extensions
will be added soon

Previously, we allowed the last message send attempt to run to maxRetries if the queue was shutdown,
which also generated warning logs. Now, if a send attempt fails, check that the queue has shutdown
and immediately return if it has

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

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

Add the ability to send blocks and receive notification when complete to messagequeue

Create a message queue to pool messages for a single peer and send them