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

feat: add fc packet

feat: add possibility to add reason to PacketParameterSerializerError

fix: do not overwrite packet types by header

feat: add bool type converter

feat: add nullable type converter

feat: allow packet attributes only on parameters