Properly use callbacks in VPN

[jdknives]

Feature description

We recently implemented callbacks for dmsg connections and disconnections. @Darkren mentioned on discord, that we need to properly implement them.

We need to properly setup callbacks from VPN client.

For STcp:

• On each connection we add direct route to the remote node via router
• On each disconnection we remove direct route to the remote node via router

For Dmsg:

• On each TCP dial to the Dmsg server we add a direct route to that server via router
• On each TCP close we remove a direct route to the remote Dmsg server via router