Added new Permissions Extension (#724)

[neekolas]

tl;dr

• Merges main into this branch, which picks up @cameronvoell's updated permissions PR
• Integrates with the new mutable metadata permissions

[neekolas]

• #741 👈
• #740
• #739
• #718
• main

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[neekolas]

I'm going to merge this into the child, since there's so much overlap and churn between the two