support quic proxy (#993)

QUIC proxy works like kcp proxy, it can proxy TCP streams and transfer data with QUIC.
QUIC has better congestion algorithm (BBR) for network with both high loss rate and high bandwidth. 
QUIC proxy can be enabled by passing `--enable-quic-proxy` to easytier in the client side. The proxy status can be viewed by `easytier-cli proxy`.

easytier/src/peers/route_trait.rs

@@ -4,11 +4,9 @@ use dashmap::DashMap;
 
 use crate::{
     common::{global_ctx::NetworkIdentity, PeerId},
-    proto::{
-        common::PeerFeatureFlag,
-        peer_rpc::{
-            ForeignNetworkRouteInfoEntry, ForeignNetworkRouteInfoKey, RouteForeignNetworkInfos,
-        },
+    proto::peer_rpc::{
+        ForeignNetworkRouteInfoEntry, ForeignNetworkRouteInfoKey, RouteForeignNetworkInfos,
+        RoutePeerInfo,
     },
 };
 
@@ -107,7 +105,7 @@ pub trait Route {
 
     async fn set_route_cost_fn(&self, _cost_fn: RouteCostCalculator) {}
 
-    async fn get_feature_flag(&self, peer_id: PeerId) -> Option<PeerFeatureFlag>;
+    async fn get_peer_info(&self, peer_id: PeerId) -> Option<RoutePeerInfo>;
 
     async fn get_peer_info_last_update_time(&self) -> std::time::Instant;