Add org owner permission to manage integrations

Part of &22859.

Problem

No permission lets an organization owner manage integration defaults.

Without one, the org admin pages cannot check who may open them.

Change

Add a permission YAML under config/authz/permissions/, for example integration/admin_organization_integration.yml (the name is a suggestion). Copy the format of organization_admin_area/access.yml.

Add a rule in organization_policy.rb. Organization owners and instance admins get the permission.

Done when

• Organization owners and instance admins have the permission.
• Other users do not.
• Policy specs cover both cases.

Status

Depends on: None

Can start now: yes