Bring back min/max Quantity for Optional Modfier Groups.

The max is what is needed here, especially with Chowly or other olo integrations. It did exist before the new back office came out. E.g., Sub cheese would be an optional modifier; if you have 4 cheese options in the group with no max rule, the customer could add all four. Basically setting you up for a service failure or customer disappointment. Many optional modifiers need to be capped, especially on a customer-facing menu like Chowly or, for us, our own digital ordering platform.