feat: Add NodeOverlay Validation Controller

[engedaam]

Fixes #N/A

Description

This PR introduces a new validation controller for NodeOverlay resources in Karpenter. The controller ensures that NodeOverlay resources with the same weight don't have conflicting configurations, which could lead to inconsistent node behavior.

Implemented NodeOverlay conflict detection: #2166

Key features:

• Validates that NodeOverlays with the same weight and overlapping requirements don't have conflicting price adjustments
• Validates that NodeOverlays with the same weight and overlapping requirements don't have conflicting capacity settings for the same resources
• Sets appropriate validation status conditions on NodeOverlay resources
• Includes comprehensive test coverage for various validation scenarios

The validation controller helps maintain consistency across NodeOverlay resources by preventing configurations that could lead to ambiguous behavior when multiple overlays apply to the same node. This ensures that when multiple NodeOverlays match a node, they don't attempt to apply conflicting modifications.

How was this change tested?

• make presubmit

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[k8s-ci-robot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: engedaam
Once this PR has been reviewed and has the lgtm label, please assign jmdeal for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[k8s-ci-robot]

PR needs rebase.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.