[chore][ping code owners] Attempt to match component and label identically when possible

[crobert-1]

Description

The logic for pinging code owners where multiple labels matched a given component returned the first in alphabetical order. This worked generally as the first alphabetical response was the minimal matching value, as shown in #38844. However, this breaks on the kafka receiver labels. The component labels are sorted in alphabetical order by the full component name. This means receiver/kafkametricsreceiver is before receiver/kafkareceiver in the list. When the receiver/kafka component is referenced, the receiver/kafkametrics label is returned as it's the first matching label in alphabetical order.

This change is to try to match component and label identically. If there's no identical match, return the first label in alphabetical order.

Existing logic has been broken out into a separate script to avoid duplicating the logic.

Link to tracking issue

Unexpected behavior was found in #39129.
receiver/kafka was the component, the label receiver/kafkametrics was added incorrectly, and the code owners were pinged for receiver/kafka correctly. When I removed the receiver/kafkametrics label and added receiver/kafka, the code owners were pinged for receiver/kafkametrics incorrectly.

Testing

# Testing issue where bug was detected
$ .github/workflows/scripts/ping-codeowners-on-new-issue.sh 
No related components were given
Adding the following labels: receiver/kafka
Pinging code owners:
- receiver/kafka: @pavolloffay @MovieStoreGuy @axw

 See [Adding Labels via Comments](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#adding-labels-via-comments) if you do not have permissions to add labels yourself.
# Testing other components
$ export COMPONENT="os:windows"
$ .github/workflows/scripts/get-label-from-component.sh

$ export COMPONENT="receiver/hostmetrics"
$ .github/workflows/scripts/get-label-from-component.sh
receiver/hostmetrics
$ export COMPONENT="receiver/kafka"
$ .github/workflows/scripts/get-label-from-component.sh
receiver/kafka
$ export COMPONENT="receiver/kafkametrics"
$ .github/workflows/scripts/get-label-from-component.sh
receiver/kafkametrics
$ export COMPONENT="extension/encoding"
$ .github/workflows/scripts/get-label-from-component.sh
extension/encoding
$ export ISSUE=39129
$ COMPONENT="receiver/kafka"
$ .github/workflows/scripts/ping-codeowners-issues.sh 
Pinging code owners for receiver/kafka: @pavolloffay @MovieStoreGuy @axw. See [Adding Labels via Comments](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#adding-labels-via-comments) if you do not have permissions to add labels yourself. For example, comment '/label priority:p2 -needs-triaged' to set the priority and remove the needs-triaged label.
$ COMPONENT="receiver/kafkametrics"
$ .github/workflows/scripts/ping-codeowners-issues.sh 
Pinging code owners for receiver/kafkametrics: @dmitryax. See [Adding Labels via Comments](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#adding-labels-via-comments) if you do not have permissions to add labels yourself. For example, comment '/label priority:p2 -needs-triaged' to set the priority and remove the needs-triaged label.

[atoulme]

I don't understand, should this code be removed or is there a follow-up?

[crobert-1]

This should be investigated in the future. From my local testing I couldn't get this check to fail, so it's more of an open question whether or not the check is useful or should be removed.