Allow simple integer enums by rawstring escaping variant names

[clux]

Addresses enums of the following form:

statusCode:
  default: 302
  description: "StatusCode is the HTTP status
    code to be used in response. \n Support: Core
    \n Note that values may be added to this enum,
    implementations must ensure that unknown values
    will not cause a crash. \n Unknown values
    here must result in the implementation setting
    the Accepted Condition for the Route to `status:
    False`, with a Reason of `UnsupportedValue`."
  enum:
  - 301
  - 302
  type: integer

like the one found in the gateway api's httproute crd (which has been copied as an integration test). Consequently, this pr fixes generation of that CRD.

The relevant generated enum now is output like this:

#[derive(Serialize, Deserialize, Clone, Debug)]
pub enum HTTPRouteRulesFiltersRequestRedirectStatusCode {
    r#_301,
    r#_302,
}

We did not have to worry about discriminants for this (and we can only really guess the discriminant from the name anyway).

There is a commented out unit test here because this exposed a bad logic setup for us in analyze_; we only catch enums that's children of something, so not top-level containers. Issue reported separately; #101