[processor/attributes] add metrics process self metrics

[hanjm]

Is your feature request related to a problem? Please describe.

The attributesprocessor and resourceprocessor are very useful to operator telemetry attributes, it seems no self metrics currently, like how many spans delete/update attributes are affected.

Describe the solution you'd like
Add some self metrics.
Describe alternatives you've considered

Additional context
Add any other context or screenshots about the feature request here.

[jpkrohling]

There are some prerequisites for this. See open-telemetry/opentelemetry-collector#4198

[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:

• processor/attributes: @boostchicken

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

[github-actions]

This issue has been closed as inactive because it has been stale for 120 days with no activity.