1. Proposed title of this feature request

Node drain reporting improvements

2. What is the nature and description of the request?

This is a request to improve observability around worker node drains and their status.

What we're looking for:

• a metric that reports node drain failures with the pods blocking it, and ideally a reason (e.g. pdbs)
• status on NodePools that reflects node drain failures, the offending pods and the reason 
• [optional] status on CAPI machine reflecting node drain failures, the offending pods and the reason 

3. Why does the customer need this? (List the business requirements here)

Managed services (ROSA/ARO HCP) don't expose node drain failures to the customer. The node drain failures are currently only available in CAPI logs. Managed services SRE is looking for a metric to automate sending notifications to customers when a node drain fails due to their workload, as well as a status on the nodepools as a general UX improvement. 

4. List any affected packages or components.

hypershift-operator, CAPI