feat: split packets definitions into separate assembly

Merge pull request #14 from Rutherther/packets-span

Rewrite packets string enumerator to use spans, add Injector for .NET 5+

feat: use ReadOnlySpan for deserialization instead of strings

Merge pull request #16 from Rutherther/packets-list-inline-serializer

Add generation of packet list inline serializer

feat: split inline generated deserialization into different methods

Merge pull request #12 from Rutherther/packets

Implement custom packet serializer

fix: check for null after popping the string enumerator level

feat: add inline packet converters generation support

feat: add checking parameter method for the generator

feat: add support for optional parameters

fix: correct generated syntax errors

feat: rewrite packet serializer generator