Add support for Python 3.10 Union syntax

[idoby]

Added support for serializing and deserializing Python 3.10 Unions coming from the syntactic sugar |
Also added tests for this case, and all existing tests also pass.

Solves #162

[patrickguenther]

I would have imagined this change to be way more complicated. Does this also work if one or more union constituents have custom deserializers?

[idoby]

I would have imagined this change to be way more complicated. Does this also work if one or more union constituents have custom deserializers?

I would assume so since all this does is detect Python's different way to represent the union syntax (A|B) and forward it to the rest of the code. So, I believe that if the original union works for the case you describe, this should work as well.

However, it's probably a good idea to add a test to cover what you're suggesting. If you know how to do that quickly, I would appreciate it. I'm not sure I can find the time to delve further into jsons and its testing code.

[patrickguenther]

I see, I think I misunderstood the pull request. Union support was already present and this PR just adds support for the new syntax.

[idoby]

I see, I think I misunderstood the pull request. Union support was already present and this PR just adds support for the new syntax.

Yes. If Python had chosen to represent the union syntax the same way as the typing.Union object, this code would not be needed at all.