fix: PUT API response does not send ValidationError when expected

[Abbas-Askari]

What

Fix the issue described in #117. The API previously just sent {"detail":"next version must be equal to 2, was 1"} instead of a ValidationError. Now the endpoint first fetches the current version from db, and send a validation error back if the version is not properly incremented.

Screenshot

{
  "detail": [
    {
      "type": "value_error",
      "loc": [
        "body",
        "version"
      ],
      "msg": "Value error, version must be exactly 2",
      "input": 4
    }
  ]
}

Fixes bug(s)

• PUT API response is ambiguous and does not send a ValidationError as expected #117