feat: add support for optional parameters

chore: remove debug attachment in source generator

fix: correct generated syntax errors

feat: rewrite packet serializer generator

fix: set enumerator level ReachedEnd to null if not known

feat: skip to last token of nested levels if possible

feat: add pinit packet

chore: remove unused usings

fix: use nullable inside of type converter repository

feat: do not remove prepared level on pop level

feat: store compiled fill functions in list type converter

fix: correctly receive nullable type in serialize

feat: make list separator char

fix: generate serializers for nullable types correctly

fix: syntax errors in list attribute generator

feat: store type converters in dictionary to speed up converting

feat: add base packet list source generators

fix: handle non-nullable values correctly in packet index code generator

feat: add possibility to add fixed length for packet lists

fix: correctly return results from type converter repository