0.86.0 – Go in chunks

Features:

• Preliminary (partial) support for chunked decoding/Chunked Decoder ()
• Use kotlinx.serialization 1.5.0
• The default policy now ignores all attributes in the xml namespace when
  found missing (it will not throw an exception). If explicitly declared
  they will still be handled.
• Implement a FileReader and FileWriter (and streams) for native to allow
  native writing of files.
• Update to Kotlin 1.8.21
• Deprecate the ktor module (in favour of ktor's own xml integration module).
  Note that that module still uses xmlutil, it just provides its own xml access
  code.

Fixes:

• Various high range unicode characters (and modifiers) were incorrectly seen
  as invalid values (relevant for emoji's)
• Still allow for explicit xml:space properties (while also handling them
  automatically).
• Update ChildCollector to use the correct/updated signature for
  polymorhpicDefaultDeserializer. "Fixes" #126 (the underlying issues are
  KT-55318
  and KT-56602)
• Support document fragments in DomReader
• Make the StAXReader not skip the StartDocument event initially.
• Make XmlBufferedReader.nextTagEvent process/ignore StartDocument.
• Made ignorable whitespace more consistent. #128
• Fix handling of isCollectingNSAttributes (#135). This will now properly
  handle sealed polymorphism as well as deal properly with the default
  namespace: properties without prefix will not register the null namespace.
  If the default namespace is used anywhere, this ensures that prefixes are
  used otherwise. This will avoid all occurences of xmlns="" (and
  xmlns:prefix="")
• Fix DomReader's handling of non-namespace aware elements/nodes that return
  null as localName.
• In DomReader handle the fact that JVM's xpath creates xmlns declarations for
  xmlns.
• Fix unsigned serialization of value classes.