Implement deceptive network warning dialog

...main/java/de/kuschku/quasseldroid/ui/chat/ChatActivity.kt

...eldroid/util/deceptive_networks/DeceptiveNetworkDialog.kt

app/src/main/res/layout/dialog_deceptive_network.xml

app/src/main/res/raw/untrustworthy_network_freenode.html

app/src/main/res/values/strings.xml

...schku/quasseldroid/util/safety/DeceptiveNetworkManager.kt

...chku/quasseldroid/viewmodel/helper/ChatViewModelHelper.kt

viewmodel/src/main/res/values/untrustworthy_networks.xml