fix: Normalize resources-to-ignore values to match ResourceMap keys

[rafaelperoco]

Summary

• Fixes case mismatch between --resources-to-ignore=configMaps (camelCase) and ResourceMap keys (configmaps lowercase)
• Adds unit tests for GetIgnoredResourcesList function

Problem

When using ignoreConfigMaps: true in Helm values, the generated --resources-to-ignore=configMaps flag was not working because ResourceMap uses lowercase keys. This caused permission errors when RBAC was configured without configmaps access.

Solution

Normalize the ignored resources list to lowercase in GetIgnoredResourcesList() to match ResourceMap keys.

Fixes #1068