Add SideEffect for Action to update criticality on stock change

[sebastianesch]

Adding the SideEffect to the action submitOrder updates the criticality in the list report on action execution.

cat-service.cds:

entity Books as projection on codejam.Books actions {
            @Common.SideEffects: {TargetEntities: ['/CatalogService.Books/RootEntity']}
            action submitOrder(quantity : Integer) returns {
                stock : Integer
            };
        };