Reorganize modules to add a fuzz target

.../de/justjanne/libquassel/protocol/util/reflect/subtype.kt

.../de/justjanne/libquassel/protocol/util/updateStateFlow.kt

...tlin/de/justjanne/libquassel/protocol/variant/QVariant.kt

.../de/justjanne/libquassel/protocol/variant/QVariantList.kt

...n/de/justjanne/libquassel/protocol/variant/QVariantMap.kt

.../libquassel/protocol/variant/WrongVariantTypeException.kt

...otlin/de/justjanne/libquassel/protocol/variant/indexed.kt

...de/justjanne/libquassel/protocol/types/SignedIdProxy.java

...anne/libquassel/protocol/util/collections/PairsProxy.java

...quassel/protocol/connection/ClientHeaderSerializerTest.kt

.../justjanne/libquassel/protocol/features/FeatureSetTest.kt

...justjanne/libquassel/protocol/io/ChainedByteBufferTest.kt

.../de/justjanne/libquassel/protocol/io/StringEncoderTest.kt

...ocol/serializers/handshake/ClientInitAckSerializerTest.kt

...l/serializers/handshake/ClientInitRejectSerializerTest.kt

...rotocol/serializers/handshake/ClientInitSerializerTest.kt

...col/serializers/handshake/ClientLoginAckSerializerTest.kt

.../serializers/handshake/ClientLoginRejectSerializerTest.kt

...otocol/serializers/handshake/ClientLoginSerializerTest.kt

...tocol/serializers/handshake/CoreSetupAckSerializerTest.kt