KERML11 — Check checkConnectorTypeFeaturing does not work for variable features

In 8.3.4.5.3 Connector, the constraint checkConnectorTypeFeaturing is intended to prevent a situation such as the following, when a related feature of a connector is not "featured within" the featuring type of the connector:

class C {
    feature x;
    feature y {
        feature z;
        connector x to z; // related feature "x" violates constraint
    }
}

However, if the connector and the related feature are both variable features, then the constraint is not violated:

class C {
    var feature x;
    var feature y : Occurrence {
        var feature z;
        var connector x to z; // no violation
    }
}

This was not intended. It happens because the constraint uses the operation isFeatureWithin which, for variable features, uses canAccess. The operation `canAccess` was changed to allow access in outer scopes, but this unintentionally resulting in a weakening of the checkConnectorTypeFeaturing constraint in regard to variable features.