Add missing serialization calls for saved data structs

[dyanikoglu]

Not sure why those calls were not included in serialize functions.

[rweber89]

@dyanikoglu this change doesnt include a version for the manual serialization, so not all changes in newer version will be backwards compatible.

[MothDoctor]

Indeed, this might break loading already created saves in released games. Is there a specific reason why you proposed these changes? I understand that current code feels incomplete, but works fine with properties marked as SaveGame?

[dyanikoglu]

In my custom save system, I'm serializing those structs manually and writing into saved data. If it's likely break compatibility with existing projects, the PR can be closed.