Collect Validate errors for a resource and display them at once

[rileykarson]

MMv1 errors are inconsistent in how much information is available. Some format strings show the affected property/resource and others don't. I'm looking to clear that up- as well as stop the process dying from a log.Fatalf on any issue. Since Validate does surface-level checking of yaml data we can typically proceed after seeing an error, allowing us to collect multiple errors instead of dying immediately.

We could theoretically push this further- since resources are mostly or entirely independent- and collect errors across all files before dying. For now I collected all errors in the current resource, prefixed them all with the resource file they came from, and sent a fatal error after validating the entire resource. Currently a draft, looking for any thoughts/concerns/feedback before cleaning up and creating a merge-ready PR.

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[c2thorn]

seems simply better than what we had before, do you have example output that you used

[rileykarson]

The errors on the PR are from the second commit that introduces a resource and field level issue in the same resource! Any of them- like https://github.com/GoogleCloudPlatform/magic-modules/actions/runs/21299668917/job/61314007939?pr=16207 - work