fix(horizontalpodautoscaler): add selector labels where applicable for hpa spec|status target metrics

[DP19]

What this PR does / why we need it:
Similar to the issue found in #2408 since prometheus 2.52 it now complains about duplicate metric values. Since some of the hpa metrics for external, pod, and object metrics can have the same name but different selectors we should add these labels to help differentiate between these metrics (#2405)

How does this change affect the cardinality of KSM: (increases, decreases or does not change cardinality)
This may increase cardinality somewhat if these selectors change between hpa revisions but this should fix an issue with the duplicates that already exist

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #2405

I didn't dig too deep but the quick search i did didn't yeild any other patterns for things like this. I just went with the approach of adding in metric labels all prepended with selectorlabel so if you have a hpa like the one shown in the issue:
#2405 (comment)

these metrics would look like:

kube_horizontalpodautoscaler_spec_target_metric{horizontalpodautoscaler="payments-gateway",metric_name="amqp_messages_unacknowledged",metric_target_type="AverageValue",namespace="payments",selectorlabel_queue="queue_one"} 40
kube_horizontalpodautoscaler_spec_target_metric{horizontalpodautoscaler="payments-gateway",metric_name="amqp_messages_unacknowledged",metric_target_type="AverageValue",namespace="payments",selectorlabel_queue="queue_two"} 40
kube_horizontalpodautoscaler_spec_target_metric{horizontalpodautoscaler="payments-gateway",metric_name="amqp_messages_unacknowledged",metric_target_type="AverageValue",namespace="payments",selectorlabel_queue="queue_three"} 40
...

where selectorlabel will be any number of labels within same with the selector.matchLabels field of the metric. This is the same for kube_horizontalpodautoscaler_status_target_metric as well

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[dgrisonnet]

/assign @CatherineF-dev
/triage accepted

[CatherineF-dev]

We think cardinality might be an issue.

Will #2614 fix the problem?

[DP19]

We think cardinality might be an issue.

Will #2614 fix the problem?

Yup that should fix it as well. I'll close this out, thanks!