Improve state saving/restoring

.../java/de/kuschku/quasseldroid/service/BacklogRequester.kt

...in/java/de/kuschku/quasseldroid/service/QuasselService.kt

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

...de/kuschku/quasseldroid/ui/chat/input/ChatlineFragment.kt

...chku/quasseldroid/ui/chat/messages/MessageListFragment.kt

...va/de/kuschku/quasseldroid/ui/chat/topic/TopicActivity.kt

...va/de/kuschku/quasseldroid/ui/chat/topic/TopicFragment.kt

...java/de/kuschku/quasseldroid/util/backport/OsConstants.kt

...chku/quasseldroid/util/backport/ReadableWrappedChannel.kt

...chku/quasseldroid/util/backport/WritableWrappedChannel.kt

...n/java/de/kuschku/quasseldroid/util/backport/codec/Hex.kt

...u/quasseldroid/util/ui/fastscroll/views/FastScroller.java

lib/src/main/java/de/kuschku/libquassel/protocol/SignedId.kt

lib/src/main/java/de/kuschku/libquassel/util/flag/Flag.kt

...src/main/java/de/kuschku/libquassel/util/flag/LongFlag.kt

...rc/main/java/de/kuschku/libquassel/util/flag/ShortFlag.kt

...de/kuschku/quasseldroid/persistence/models/MessageData.kt

...n/java/de/kuschku/quasseldroid/viewmodel/ChatViewModel.kt

...ain/java/de/kuschku/quasseldroid/viewmodel/data/Avatar.kt

...e/kuschku/quasseldroid/viewmodel/data/FormattedMessage.kt