Converter for `java.util.Optional`

[xtaixe]

There are issues with Optional and Java 17. See https://github.com/quarkusio/quarkus/issues/25413

com.thoughtworks.xstream.converters.ConversionException: No converter available
---- Debugging information ----
message             : No converter available
type                : java.util.Optional
converter           : com.thoughtworks.xstream.converters.reflection.ReflectionConverter
message[1]          : Unable to make field private static final java.util.Optional java.util.Optional.EMPTY accessible: module java.base does not "opens java.util" to unnamed module @33723e30
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Is it possible to add a converter for java.util.Optional?