Fix ser/deserialization for enums and Path

[ivanprado]

I have noticed that by default Enum and Path classes are not serialized/deserialized properly. This PR fixes the problem. It includes a few tests to check that it is working.

[lebrice]

Thanks!
Left a few minor comments

[ivanprado]

@lebrice thank you for the review!. I went through your comments and addressed them.

I've also noticed that is better to use the Enum name instead of value: the latter may not be unique and can be less representative (e.g. if automatic integers are used as value). This change was implemented in 6296025

[lebrice]

Thanks!