Additional discount configuration: Shopify-like "once_per_customer" and "allocation_limit"

[eric-makro]

Will Medusa Team have a plan to add Shopify-like "once_per_customer" and "allocation_limit" discount configuration.

• "once_per_customer"
  It's used to set whether a discount will be valid only for a single use per customer

(please check below screenshot for Shopify reference)

• "allocation_limit"
  It's used to set the number of times the discount can be allocated on the cart if eligible

(please check below screenshot for Shopify reference)

Thanks

[DidierGuyon]

@eric-makro For the once_per_customer rule, I created a pull request: #3700