Allow showing hostmask in join/part/quit messages

...va/de/kuschku/quasseldroid_ng/ui/chat/NickListFragment.kt

...uasseldroid_ng/ui/chat/messages/QuasselMessageRenderer.kt

...ku/quasseldroid_ng/ui/settings/data/AppearanceSettings.kt

...a/de/kuschku/quasseldroid_ng/ui/settings/data/Settings.kt

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

app/src/main/res/xml/preferences.xml