[UE5.4] Property tag serialization support

[joric]

Already posted an issue in another project but maybe you know what's happening there trumank/uesave#80

[scottanderson]

It looks like we'll need to add support for the new UE5.4 property tag serialization format first.

trumank/uesave@3d00ea1

[scottanderson]

PROPERTY_TAG_COMPLETE_TYPE_NAME added in https://github.com/EpicGames/UnrealEngine/commit/2807197a97259262f0eee8f3d38a1fa73f5370d6

[scottanderson]

When EUnrealEngineObjectUE5Version::PROPERTY_TAG_COMPLETE_TYPE_NAME is enabled, property tag serialization should change from (current):

FPropertyTag:
  (FString) name
  (FString) type
  (u32) size
  (u32) array index
  <type-specific extras for container types>
  (u8) terminator

to (new):

FPropertyTypeName:
  (FString) name
  (u32) count
  (FPropertyTypeName[count]) children

FPropertyTag:
  (FString) name
  (FPropertyTypeName) type
  (u32) size
  (u8) flags
  [u32] array index (flags & EPropertyTagFlags::HasArrayIndex)
  [u128] guid (flags & EPropertyTagFlags::HasPropertyGuid): 

There is also a null byte after the header and before the first property.