[Catalog] Add an additional usage option to promotions and allow admin to specify number of uses

[rpsloan]

Problem statement:

When a Catalog admin creates a promotion, they can only choose from two usage options: one time per user, or unlimited. We have a use case where a Catalog admin wants to share just one promo code to a group of users and instead of having to create one per person or having to create an unlimited one, they have asked if there's a way to set a promotion code to be set for a specific number of use, which is currently not an option.

Proposed solution:

In the dropdown for Promotions usage, add another option for an admin to set a promotion to a specific number of use. This provides the Catalog admin more flexibility on how often or how limited the use of promotion should be.

User role(s):

admin

[KataKeri]

Thanks for the submission. Added to theme.