Tidy up PendingWhisper logic, whispers to offline friends

[3vcloud]

Duplicated code, doesn't work when a friend is set to appear offline, can get a but confused if the player is also trying to send whispers at the same time

https://github.com/HasKha/GWToolboxpp/blob/547d05821e8938664be170c6fbe3915a8cf5b04f/GWToolboxdll/Windows/FriendListWindow.cpp#L154