Extend Management to support peer changes distribution (#55)

* feature: add peer sync and a server public key endpoints
* test: add Management.Sync() gRpc endpoint test
* feat: implement peer sync
* docs: added some comments to the Management server
* chore: use for loop over channel when monitoring peer updates
* fix: exit infinite loop when sending updates to peers
* test: add multiple concurrent peers test for management service
* chore: remove unused test
* fix: reduce the amount peers for a concurrent peer update test

Co-authored-by: braginini <m.bragin@wiretrustee.com>

signal/client.go

@@ -110,7 +110,7 @@ func (c *Client) connect(key string, msgHandler func(msg *proto.Message) error)
 	md := metadata.New(map[string]string{proto.HeaderId: key})
 	ctx := metadata.NewOutgoingContext(c.ctx, md)
 
-	stream, err := c.realClient.ConnectStream(ctx)
+	stream, err := c.realClient.ConnectStream(ctx, grpc.WaitForReady(true))
 
 	c.stream = stream
 	if err != nil {