content Deserializer
fun Set<SerializerMapping<out EventContent>>.contentDeserializer(type: String): KSerializer<out EventContent>
fun Set<SerializerMapping<out EphemeralEventContent>>.contentDeserializer(type: String): KSerializer<out EphemeralEventContent>
fun Set<SerializerMapping<out EphemeralDataUnitContent>>.contentDeserializer(type: String): KSerializer<out EphemeralDataUnitContent>
fun Set<SerializerMapping<out GlobalAccountDataEventContent>>.contentDeserializer(type: String): KSerializer<out GlobalAccountDataEventContent>
fun Set<SerializerMapping<out RoomAccountDataEventContent>>.contentDeserializer(type: String): KSerializer<out RoomAccountDataEventContent>
fun Set<SerializerMapping<out RoomEventContent>>.contentDeserializer(type: String): KSerializer<out RoomEventContent>
fun Set<SerializerMapping<out StateEventContent>>.contentDeserializer(type: String): KSerializer<out StateEventContent>
fun Set<SerializerMapping<out MessageEventContent>>.contentDeserializer(type: String): KSerializer<out MessageEventContent>
fun Set<SerializerMapping<out ToDeviceEventContent>>.contentDeserializer(type: String): KSerializer<out ToDeviceEventContent>