Use literal unions in python enum codegen

[jprochazk]

What

Strings now autocomplete in places where we use enum classes that get converted from strings.

Follow up to #6407

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[github-actions]

Deployed docs

Commit	Link
970bcab	https://landing-45oyyhziw-rerun.vercel.app/docs

[Wumpf]

(we had a bit a discussion about casing/style of the enum values and ended up with this here)

👍