Implement Hashable protocol for data classes

[X1nto]

Since data classes already provide hashValue(), it would make sense for the Swift side to conform data classes to the Hashable protocol automatically. This would make using the data classes in SwiftUI views such as List much easier without specifying the id. This probably isn't very hard to do and I'd be more than happy to PR, but you don't seem to accept PRs due to internal unit tests.