Add IBM MQ scaler e2e test

[ayoyu]

Description of what has been changed:

• Add e2e tests for the IBM MQ scaler
• Add error handling when the commandResponse[0].parameters field is missing in case of an error as discussed in this comment Add e2e test for IBM MQ Scaler #1287 (comment) . Reference about the response body format (JSON schema): https://www.ibm.com/docs/en/ibm-mq/9.3?topic=adminactionqmgrqmgrnamemqsc-post-json-formatted-command#q133340___responseformat__title__1
  For example when querying the current queue depth of a non existing queue:

{
  "commandResponse": [{
    "completionCode": 2,
    "reasonCode": 2085,
    "message": ["AMQ8147E: IBM MQ object bar not found."]
  }],
  "overallReasonCode": 3008,
  "overallCompletionCode": 2
}

Example from the operator log with the new error handling:

2024-06-02T16:18:50Z	INFO	Detected resource targeted for scaling	{"controller": "scaledobject", "controllerGroup": "keda.sh", "controllerKind": "ScaledObject", "ScaledObject": {"name":"ibmmq-consumer","namespace":"ibmmq-test-ns"}, "namespace": "ibmmq-test-ns", "name": "ibmmq-consumer", "reconcileID": "c064a17e-7cd1-4a1e-ba90-c3dc8f4b4a6d", "resource": "apps/v1.Deployment", "name": "ibmmq-consumer"}
+2024-06-02T16:18:51Z	ERROR	scale_handler	error getting scale decision	{"scaledObject.Namespace": "ibmmq-test-ns", "scaledObject.Name": "ibmmq-consumer", "scaler": "IBMMQScaler", "error": "error inspecting IBM MQ queue depth: failed to get the current queue depth parameter, reason: AMQ8147E: IBM MQ object FAKE.QUEUE not found."}
github.com/kedacore/keda/v2/pkg/scaling.(*scaleHandler).getScalerState
	/workspace/pkg/scaling/scale_handler.go:780
github.com/kedacore/keda/v2/pkg/scaling.(*scaleHandler).getScaledObjectState.func1
	/workspace/pkg/scaling/scale_handler.go:633

• Fix an embedded nil error by removing it

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 our Helm chart (repo) (if applicable, ie. when deployment manifests are modified)
• A PR is opened to update the documentation on (repo) (if applicable)
• Commits are signed with Developer Certificate of Origin (DCO - learn more)

Fixes #1287

[zroubalik]

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

[zroubalik]

great, thanks a lot! Do you think you can also add a simple unit test for the fix you included?

[ayoyu]

great, thanks a lot! Do you think you can also add a simple unit test for the fix you included?

Yes I will add it.

[zroubalik]

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

[ayoyu]

great, thanks a lot! Do you think you can also add a simple unit test for the fix you included?

Test added for getQueueDepthViaHTTP related to the fix.

[zroubalik]

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