[CC-5719] Add support for builtin global-read-only policy (#18319)
* [CC-5719] Add support for builtin global-read-only policy
* Add changelog
* Add read-only to docs
* Fix some minor issues.
* Change from ReplaceAll to Sprintf
* Change IsValidPolicy name to return an error instead of bool
* Fix PolicyList test
* Fix other tests
* Apply suggestions from code review
* Fix state store test for policy list.
* Fix naming issues
* Update acl/validation.go
* Update agent/consul/acl_endpoint.go
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Co-authored-by: Jeremy Jacobson <jjacobson93@users.noreply.github.com>
Co-authored-by: Paul Glass <pglass@hashicorp.com>
Co-authored-by: Chris Thain <32781396+cthain@users.noreply.github.com>
hc-github-team-consul-core