[ENHANCEMENT]: support `enums`

[Zer0xxxx]

Feature Description

Currently, enums are not supported in Orange ORM.
As we discussed, it could relatively "easily" be implemented.

Related to: #96 (#96 (comment))

[Zer0xxxx]

Btw, I think it should be typed also.
Just calling a validation function on it will help to keep the enum safe at runtime, but not at compile time. :/

Likewise:

const wolfgang = await db.team.insert({
  'lang': '...', // * ... No IntelliSense?
  // * ...
});

[lroal]

Yes, of course 😊