Move as much functionality as possible into the state holders

...e/justjanne/libquassel/protocol/syncables/AliasManager.kt

.../de/justjanne/libquassel/protocol/syncables/IrcChannel.kt

...lin/de/justjanne/libquassel/protocol/syncables/IrcUser.kt

...lin/de/justjanne/libquassel/protocol/syncables/Network.kt

.../libquassel/protocol/syncables/state/AliasManagerState.kt

...ne/libquassel/protocol/syncables/state/IrcChannelState.kt

...janne/libquassel/protocol/syncables/state/IrcUserState.kt

...janne/libquassel/protocol/syncables/state/NetworkState.kt

.../de/justjanne/libquassel/protocol/util/irc/IrcISupport.kt