fix: app freeze on quit (#1804)

* fix: app freeze on quit

* fix: typo in VpnConnection destructor

* add trace info

* add more trace info

* set timelimit for flushDns

* Refactor IpcClient::Interface access logic

* cleanup unused variable

* cleanup trace info

* fix: remove second disconnect from VPN on app close

* this object will be deleted at app close

* Don't terminate VPN thread on Linux

* Revert "Don't terminate VPN thread on Linux"

This reverts commit 20e4ea2d4a.

* disconnect all signals from vpnconnection on exit

* add interruption request on vpnConnectionThread

* use checktimer only for iOS

* disconnect all signals from vpnconnection on exit

* disconnect signals on exit before VPN disconnect

* add disconnectSlots method

* fix: add allow traffic rules on killswitch disable

* wait for response from service before object destroy

* change disconnect from vpn order

* add delay for connection close

* change disconnect method order

* use stop method for protocol disconnecect

* change disconnect method order

* allow dns traffic after app close

* delete tun on disconnect

---------

Co-authored-by: vkamn <vk@amnezia.org>

ipc/ipcserver.cpp

@@ -83,7 +83,7 @@ bool IpcServer::routeDeleteList(const QString &gw, const QStringList &ips)
     return Router::routeDeleteList(gw, ips);
 }
 
-void IpcServer::flushDns()
+bool IpcServer::flushDns()
 {
 #ifdef MZ_DEBUG
     qDebug() << "IpcServer::flushDns";
@@ -161,13 +161,14 @@ bool IpcServer::restoreResolvers() {
     return Router::restoreResolvers();
 }
 
-void IpcServer::StartRoutingIpv6()
+bool IpcServer::StartRoutingIpv6()
 {
-    Router::StartRoutingIpv6();
+    return Router::StartRoutingIpv6();
 }
-void IpcServer::StopRoutingIpv6()
+
+bool IpcServer::StopRoutingIpv6()
 {
-    Router::StopRoutingIpv6();
+    return Router::StopRoutingIpv6();
 }
 
 void IpcServer::setLogsEnabled(bool enabled)