[Misc] Minor refactor the PodAutoscaler codes

[Jeffwan]

Pull Request Description

1. I add some TODOs
2. remove v(3). log level. Let's be consistent and make sure it's either empty level or V(4)
3. Resolve some naming issues
4. Update crd and add conditions to follow up

Related Issues

Resolves: #[Insert issue number(s)]

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[kr11]

looks good to me.