Add read_admin_monitoring permission

What does this MR do and why?

This is the first in a series of merge requests introducing the read_admin_monitoring permission, which will provide read-only access to specific areas of the Admin Area.

Changes in this MR:

• Adds a configuration file to define the new read_admin_monitoring permission.
• Introduces a feature flag to control the rollout and usage of this permission.
• Includes placeholder specs to track incremental progress and ensure comprehensive testing in future MRs.

This change lays the foundation for incremental development, ensuring flexibility while enabling early feedback during the rollout process.

References

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• #507959 (closed)

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