refactor scraper in azuremonitorreceiver

[nslaughter]

Component(s)

receiver/azuremonitor

Describe the issue you're reporting

The azuremonitorreceiver scraper needs refactoring to clarify code, which will allow us to address bugs with zero-values sometimes as reported in #34265.

[github-actions]

Pinging code owners for receiver/azuremonitor: @nslaughter @codeboten. See Adding Labels via Comments if you do not have permissions to add labels yourself.

[crobert-1]

Issue was filed by a code owner and makes sense to me, removing needs triage.

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• receiver/azuremonitor: @nslaughter @codeboten

See Adding Labels via Comments if you do not have permissions to add labels yourself.