TUN-8415: Refactor capnp rpc into a single module

Combines the tunnelrpc and quic/schema capnp files into the same module.

To help reduce future issues with capnp id generation, capnpids are
provided in the capnp files from the existing capnp struct ids generated
in the go files.

Reduces the overall interface of the Capnp methods to the rest of
the code by providing an interface that will handle the quic protocol
selection.

Introduces a new `rpc-timeout` config that will allow all of the
SessionManager and ConfigurationManager RPC requests to have a timeout.
The timeout for these values is set to 5 seconds as non of these operations
for the managers should take a long time to complete.

Removed the RPC-specific logger as it never provided good debugging value
as the RPC method names were not visible in the logs.

cmd/cloudflared/tunnel/cmd.go

@@ -78,8 +78,8 @@ const (
 	// hostKeyPath is the path of the dir to save SSH host keys too
 	hostKeyPath = "host-key-path"
 
-	// udpUnregisterSessionTimeout is how long we wait before we stop trying to unregister a UDP session from the edge
-	udpUnregisterSessionTimeoutFlag = "udp-unregister-session-timeout"
+	// rpcTimeout is how long to wait for a Capnp RPC request to the edge
+	rpcTimeout = "rpc-timeout"
 
 	// writeStreamTimeout sets if we should have a timeout when writing data to a stream towards the destination (edge/origin).
 	writeStreamTimeout = "write-stream-timeout"
@@ -695,7 +695,7 @@ func tunnelFlags(shouldHide bool) []cli.Flag {
 			Hidden: true,
 		}),
 		altsrc.NewDurationFlag(&cli.DurationFlag{
-			Name:   udpUnregisterSessionTimeoutFlag,
+			Name:   rpcTimeout,
 			Value:  5 * time.Second,
 			Hidden: true,
 		}),

cmd/cloudflared/tunnel/configuration.go

@@ -246,7 +246,7 @@ func prepareTunnelConfig(
 		EdgeTLSConfigs:              edgeTLSConfigs,
 		FeatureSelector:             featureSelector,
 		MaxEdgeAddrRetries:          uint8(c.Int("max-edge-addr-retries")),
-		UDPUnregisterSessionTimeout: c.Duration(udpUnregisterSessionTimeoutFlag),
+		RPCTimeout:                  c.Duration(rpcTimeout),
 		WriteStreamTimeout:          c.Duration(writeStreamTimeout),
 		DisableQUICPathMTUDiscovery: c.Bool(quicDisablePathMTUDiscovery),
 	}