Adjust Json field handling

[jaschaephraim]

This is an attempt to address https://github.com/chrishoermann/zod-prisma-types/issues/134 The relevant tests still pass but I'm not sure if I'm taking all use cases into consideration.

• Uses JsonValue instead of InputJsonValue for required Json model fields
• Adjusts transformJsonNull

Misc fixes:

• updates generator version in usage workspace package.json
• updates extendedDMMF import path in tests

[chrishoermann]

I'll close this pull request since this should be handled properly as of version 3.0.0