[Observability] Requesting a new metrics for "Delete Scope" failure

When a scope deletion fails for any reason we do not have a metric to keep track and alert on the failure. The failures will be logged on the customer nodes but there is no observable metrics. 

As a part of the [Alert Review Exercise|https://docs.google.com/spreadsheets/d/1aFueZsvxCC2If11OLD0j-x8ieHsvtxuxuOTXrO0aKVI/edit#gid=0&range=53:53 SRE team has requested this metrics and K/V team has agreed to provide one.