OpenFGA MySQL backend: case-insensitive collation on identifier columns causes incorrect authorization decisions

OpenFGA is an authorization/permission engine built for developers. Prior to 1.18.0, when MySQL is being used as the datastore and authorization decisions rely on case-sensitive user strings, the tuple, changelog, and authorization_model identifier columns can compare case-distinct values such as user:Alice and user:alice as equivalent, causing two distinct check requests to return the same response. This issue is fixed in 1.18.0.