Add metric to Solace Scaler

[dennis-brinley]

Added new metric: messageReceiveRateTarget to Solace Scaler

Checklist

• I have verified that my change is according to the deprecations & breaking changes policy
• Tests have been added
• Changelog has been updated and is aligned with our changelog requirements
• A PR is opened to update the documentation on Add metric to Solace Scaler keda-docs#1150
• Commits are signed with Developer Certificate of Origin (DCO - learn more)

Fixes #4665

[zroubalik]

Lookin good, please fix the e2e test - see Static Checks failure, you can ignore the "Welcome PR" failure.

[zroubalik]

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

[dennis-brinley]

@zroubalik - there were problems with the helm chart references (the chart url context changed) - which I didn't detect because I was skipping that part of the test. I updated the code and ran the test successfully on my machine. Should be good to go.

[zroubalik]

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

[zroubalik]

LGTM

[zroubalik]

@dennis-brinley it is not possible to merge this PR due to some conflicts, could you please rebase your branch? Thanks!

[dennis-brinley]

merge conflict should be resolved

[zroubalik]

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

[zroubalik]

@dennis-brinley I can see that your rebase unfortunately included additional commits in your PR. You can see that there are some unrelevant changes. Could you please fix that?

[dennis-brinley]

chopped and re-committed

[dennis-brinley]

Tests failed on predictkube scaler. I don't think there is anything I can do about that directly.

2023/06/20 20:54:39 🚀 starting mock grpc server. On host 0.0.0.0, with port: 40761
    predictkube_scaler_test.go:225: get: {{10130000 -3} {<nil>}  DecimalSI}, want: {{10130 0} {<nil>}  DecimalSI}, predictMetric: 10130
    predictkube_scaler_test.go:221: 
        	Error Trace:	/__w/keda/keda/pkg/scalers/predictkube_scaler_test.go:221
        	Error:      	Received unexpected error:
        	            	Post "http://demo.robustperception.io:9090/api/v1/query_range": read tcp4 172.19.0.2:60472->157.245.26.111:9090: i/o timeout
        	Test:       	TestPredictKubeGetMetrics
    predictkube_scaler_test.go:222: 
        	Error Trace:	/__w/keda/keda/pkg/scalers/predictkube_scaler_test.go:222
        	Error:      	Not equal: 
        	            	expected: 0
        	            	actual  : 1
        	Test:       	TestPredictKubeGetMetrics
--- FAIL: TestPredictKubeGetMetrics (20.08s)
panic: runtime error: index out of range [0] with length 0 [recovered]
	panic: runtime error: index out of range [0] with length 0

goroutine 11020 [running]:
testing.tRunner.func1.2({0x2495f80, 0x400363a060})
	/usr/local/go/src/testing/testing.go:1526 +0x1c8
testing.tRunner.func1()
	/usr/local/go/src/testing/testing.go:1529 +0x364
panic({0x2495f80, 0x400363a060})
	/usr/local/go/src/runtime/panic.go:884 +0x1f4
github.com/kedacore/keda/v2/pkg/scalers.TestPredictKubeGetMetrics(0x400309c680)
	/__w/keda/keda/pkg/scalers/predictkube_scaler_test.go:223 +0x3b4
testing.tRunner(0x400309c680, 0x27d12f8)
	/usr/local/go/src/testing/testing.go:1576 +0x104
created by testing.(*T).Run
	/usr/local/go/src/testing/testing.go:1629 +0x370
FAIL	github.com/kedacore/keda/v2/pkg/scalers	28.280s

[JorTurFer]

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