New Authentication and Authorization section

What does this MR do and why?

This MR introduces a new CODEOWNERS section called Authentication and Authorization which is responsible for matching files that are related to all things authentication and authorization.

• ⚠ This new Authentication and Authorization section is non-optional and so means MRs will require approval from the responsible parties.
• ⚠ The 'Code Owner approval' switch is not currently enabled for master so this change will not be enforced. The activation of this will be communicated broadly and scheduled for a time following the merge of this MR.
• ⚠ Codeowners can be bypassed for moved files will need to be investigated and potentially addressed before mandatory approvals can be enabled.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.