Support Secure WebSocket

Add full WSS support to public server list (using wss_port, overriding
insecure port), favorite servers list, and direct connections, and show
which servers are secure.

Revert the upstream's removal of `legacy` ServerInfo field, as I use it
to filter out legacy servers. To differentiate schemes, the `scheme`
field is used, either "ws" or "wss". I don't see the reason to add "tcp"
protocol when we don't even support it.

For the UI, add icons for secure and insecure connections. Highlight
secure servers with a green background.

In the favorite server dialog, a checkbox was added to select whether
the server is using WSS.

In the direct connection dialog, support "wss" scheme and default ports:
80 for WS, 443 for WSS, as per the WebSocket specification.

2 files changed, 3 insertions, 2 deletions

diff --git a/src/network/serverinfo.h b/src/network/serverinfo.h
index de91a011..b7e00697 100644
--- a/src/network/serverinfo.h
+++ b/src/network/serverinfo.h
@@ -9,7 +9,8 @@ public:
   QString description;
   QString address;
   quint16 port = 0;
-  QString protocol = "ws";
+  bool legacy = false;
+  QString scheme = "ws";
 
   QString toString() const;
 };
diff --git a/src/network/websocketconnection.cpp b/src/network/websocketconnection.cpp
index e9cc1ef9..d51cdcaf 100644
--- a/src/network/websocketconnection.cpp
+++ b/src/network/websocketconnection.cpp
@@ -32,7 +32,7 @@ void WebSocketConnection::connectToServer(const ServerInfo &server)
   disconnectFromServer();
 
   QUrl url;
-  url.setScheme(server.protocol);
+  url.setScheme(server.scheme);
   url.setHost(server.address);
   url.setPort(server.port);