Disambiguate duplicate `Member` names

[clux]

This adds a safer name mutation strategy in output.rs, by checking to see if a pascal/snake rename would generate a duplicate name, and then suffixing the name if it does to keep it rust compatible.

This is to fix certain pathological cases like #165.

This solution does not drop information, and always manages to include everything in the struct (even if we don't know which one will eventually go away, like the case with relabeling actions).

Annotated Example

Using the PodMonitor CRD with the clashing relabeling actions, this is what we now produce on the the struct by default (minus my explaining comments about where the member name came from):

#[derive(Serialize, Deserialize, Clone, Debug)]
pub enum PodMonitorPodMetricsEndpointsMetricRelabelingsAction {
    #[serde(rename = "replace")]
    Replace, // originally named "replace" in the spec (a deprecated name)
    #[serde(rename = "Replace")]
    ReplaceX, // originally named "Replace" in the spec
    #[serde(rename = "keep")]
    Keep, // originally named "keep" in the spec (deprecated)
    #[serde(rename = "Keep")]
    KeepX, // originally named "Keep" in the spec

    #[serde(rename = "labelmap")]
    Labelmap, // originally named "labelmap" in the spec (deprecated)
    LabelMap, // originally named "LabelMap" in the spec
    /// ....
}

Caveats

• You might have to rename the code down the line if "deprecated" attributes got removed (removing the need for the suffix)
• You can end up with extremely similar member names, but there's also no way to avoid this without actually removing variants we would ideally want to remove (no deprecated attrs). You reap what you sow.

Maybe in the future if the OpenAPI spec can include deprecated attrs, we can remove this logic.

(This PR was originally trying to deduplicate members by name, but this ended up picking the wrong names, leaving the good ones unreachable by chance.)

[sebhoss]

I like this a lot & it completely removes the need for my home grown solution (I have used yq to remove duplicate fields before passing the modified YAML to kopium). Running this against all CRDs in kube-custom-resources-rs yields a single warning though: The natOutgoing and nat-outgoing fields in an Calico IPPool resource are not enums and thus should use snake_case. The generated code is here: https://github.com/metio/kube-custom-resources-rs/blob/kopium-206/kube-custom-resources-rs/src/crd_projectcalico_org/v1/ippools.rs#L38

[clux]

thanks @sebhoss , have added a smarter suffixing var to deal with the differences between struct and enum members now!

[clux]

also nice to see all that manual override code go away :smile:

[sebhoss]

yeah this solution here is a lot better since it retains all enums/fields so people can actually use all possible values (even though they are deprecated upstream).

Great stuff - thanks a lot!