refactor: Improve handshake resiliency of peer (#95)

* fix: Synchronize peer logging with a channel

We were depending on the close mutex to properly
report connection state. This ensures the RTC
connection is properly closed before returning.

* Disable pion logging

* Remove buffer

* Try ICE servers

* Remove flushed

* Add diagram explaining handshake

* Fix candidate accept ordering

* Add debug logging to peerbroker

* Fix send ordering

* Lock adding ICE candidate

* Add test for negotiating out of order

* Reduce connection to a single negotiation channel

* Improve test times by pre-installing Terraform

* Lock remote session description being applied

* Organize conn

* Revert to multi-channel setup

* Properly close ICE gatherer

* Improve comments

* Try removing buffered candidates

* Buffer local and remote messages

* Log dTLS transport state

* Add pion logging

coderd/userpassword/userpassword_test.go

@@ -1,3 +1,7 @@
+// This test runs slowly on MacOS instance, and really
+// only needs to run on Linux anyways.
+//go:build linux
+
 package userpassword_test
 
 import (