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>

client/vpnconnection.h

@@ -56,6 +56,7 @@ public slots:
     void deleteRoutes(const QStringList &ips);
     void flushDns();
     void onKillSwitchModeChanged(bool enabled);
+    void disconnectSlots();
 
 signals:
     void bytesChanged(quint64 receivedBytes, quint64 sentBytes);
@@ -95,6 +96,7 @@ private:
 
    void appendSplitTunnelingConfig();
    void appendKillSwitchConfig();
+   bool InterfaceReady();
 };
 
 #endif // VPNCONNECTION_H