PR#9357 Backport for 1.35: Ensure HasInstance and NodeGroupForNode derive from the same list, backport ignore string case

[jlamillan]

Which component this PR applies to?

cluster-autoscaler (OCI provider code)

What type of PR is this?

/kind bug
/kind cleanup

What this PR does / why we need it:

• Backport of PR 9357 to 1.35
• Backport of related PR 9250 to 1.35

This PR adds a fix to HasInstance() to ensure that it and NodeGroupForNode() derive their instance lists the same way for consistent lifecycle mapping. It also adds a number of other incremental updates and other improvements to the OCI (Instance-Pool) cloud provider after attempting to debug the issue:

• updated HasInstance() implementation to more closely align with and NodeGroupForNode() to avoid potential mismatches for newly scaled nodes.
• added log messages and add debug statements for easier troubleshooting at higher log levels.
• avoid unnecessary searches for OKE nodes in instance pools.
• Pulls in recent commit 1a7e964, which may actually address at least part of the root cause

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

I am the original author of the provider code in question and listed in the OWNERS file.

Does this PR introduce a user-facing change?

Improved logging for and other incremental improvements. 

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jlamillan

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• cluster-autoscaler/cloudprovider/oci/OWNERS [jlamillan]

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[jlamillan]

/retest