Summary: Access to structural tables currently depends on SchemaEdit permission. We now make an exception for owner access to _grist_ACLResources and _grist_ACLRules, giving them unconditional access. It was too easy for owners to lock themselves out of editing access rules.
Test Plan: added test
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2790