Refactor Apache Kafka scaler config

[wozniakjan]

Refactor Apache Kafka scaler config using declarative parser from #5676. This PR also introduces a new field tag option range. This tag helps with config options that don't want to enumerate all of the values but instead generate as range (or multiple ranges) bounded by from and to (or multiple from's and to's).

Example usage:

keda/pkg/scalers/scalersconfig/typed_config_test.go

Lines 523 to 537 in f905add

	sc := &ScalerConfig{
	TriggerMetadata: map[string]string{
	"range": "5-10",
	"multiRange": "5-10, 15-20",
	"dottedRange": "2..7",
	"wrongRange": "5..3",
	},
	}
	type testStruct struct {
	Range []int `keda:"name=range, order=triggerMetadata, rangeSeparator=-"`
	MultiRange []int `keda:"name=multiRange, order=triggerMetadata, rangeSeparator=-"`
	DottedRange []int `keda:"name=dottedRange, order=triggerMetadata, rangeSeparator=.."`
	WrongRange []int `keda:"name=wrongRange, order=triggerMetadata, rangeSeparator=.."`
	}

Checklist

• I have verified that my change is according to the deprecations & breaking changes policy
• Changelog has been updated and is aligned with our changelog requirements
• Commits are signed with Developer Certificate of Origin (DCO - learn more)

Relates to #5797

[wozniakjan]

/run-e2e apache_kafka
Update: You can check the progress here

[dttung2905]

@wozniakjan Oh I did not know you are working on apache_kafka_scaler.go. I'm working on the kafka_scaler.go but the progress is no where matching yours. Do you want to work on kafka_scaler.go too, since the code for both scalers are largely similar?

[wozniakjan]

@wozniakjan Oh I did not know you are working on apache_kafka_scaler.go. I'm working on the kafka_scaler.go but the progress is no where matching yours. Do you want to work on kafka_scaler.go too, since the code for both scalers are largely similar?

my bad, I didn't realize they were similar and I was just going in alphabetical order one scaler at a time. Sure thing, and sorry for the inconvenience. Feel free to open WIP PR with what you have for the kafka_scaler.go and I can continue.

[wozniakjan]

/run-e2e apache_kafka
Update: You can check the progress here

[wozniakjan]

ptal @kedacore/keda-contributors, @dttung2905, @SpiritZhou, not sure about the rangeSeparator, maybe I should just call it range and optionally take value for separator, otherwise assume - as default?

[zroubalik]

ptal @kedacore/keda-contributors, @dttung2905, @SpiritZhou, not sure about the rangeSeparator, maybe I should just call it range and optionally take value for separator, otherwise assume - as default?

I like this

[wozniakjan]

/run-e2e
Update: You can check the progress here

[wozniakjan]

/run-e2e
Update: You can check the progress here

[wozniakjan]

/run-e2e
Update: You can check the progress here

[wozniakjan]

ptal @kedacore/keda-contributors