[FLINK-37126] Add Validator for Autoscaler

[huyuanfeng2018]

What is the purpose of the change

Add Validator for Autoscler, Facilitates StandaloneAutoscaler to detect configuration anomalies in advance

Brief change log

• Migrate the verification part of Autoscaler in DefaultAutoscalerValidator to the Autoscaler module
• Verify the Autoscaler config separately in StandaloneAutoscaler. If there are illegal parameters, report them through events.

Verifying this change

This change added tests and can be verified as follows:

• add StandaloneAutoscalerValidatorTest Used to verify parameter verification under standloneAutoscaler
• The old test cases cover the test for Autoscaler parameter verification under the operator

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): ( no)
• The public API, i.e., is any changes to the CustomResourceDescriptors: (no)
• Core observer or reconciler logic that is regularly executed: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not documented)

[gyfora]

Any update on this?

[huyuanfeng2018]

Any update on this?

Thanks for @gyfora ping, it's been too long I forgot about this PR, I'll keep pushing forward

[huyuanfeng2018]

@gyfora Could you help review this PR when you have time? Thank you very much ~

[gyfora]

The changes look good, but I would remove the extra interface added

[gyfora]

Instead of making this an interface with a default implementation, can we simply make this a regular class and just use it directly? AutoscalerValidator that contains the implementation. If later we want to make it pluggable then we can extract the interface but now this is just boilerplate