version two of feature-gate prototype

featuregate-v2.go

type FeatureHistory struct {
        Changes        map[K8sVersion][]HistoryEvent
        reverseMapping map[HistoryEvent]semver.Version
        built          bool
}

type FeatureSpec struct {
        // Default is the default enablement state for the feature
        Default bool
        // LockToDefault indicates that the feature is locked to its default and cannot be changed
        LockToDefault bool
        // PreRelease indicates the current maturity level of the feature
        PreRelease prerelease
        // History is a recording of all changes made to the feature.
        History FeatureHistory
}

var ExampleFeature := testGAGate: {
    Default:    true,
    PreRelease: GA,
    History: (&FeatureHistory{
        Changes: map[K8sVersion][]HistoryEvent{
            V1_27: {PromotedToAlpha},
            V1_28: {PromotedToBeta, DefaultEnabled},
            V1_29: {PromotedToGA},
        },
    }).Build(),
}