Feature request: Unions support

[chf0x]

Hello BinSync Team,

Thank you for the great lib! I'd like to request the addition of Unions to Artifacts supported by BinSync. This feature would complement the existing support for structs, enums, and other user-created types, enhancing the tool's utility for RE.

Thank you for considering this enhancement.

[matty45]

I would also like this feature to be implemented as some structs that I have been using contain unions, and that is already causing me a whole lot of bother trying to share them.