feat: allow modifier quantity

[kevinlee11]

In preparation for modifier quantities, allow the SDK to accept an array of strings (existing behaviour) or an array of ChoiceSelection objects.

Note that at the moment, the platform will only accept a modifier quantity of 1.

[github-actions]

size-limit report 📦

Path	Size
lib/index.js	6.04 KB (+0.77% 🔺)
lib/index.umd.cjs	6.2 KB (+0.67% 🔺)

[github-actions]

📊 Package size report   0.4%↑

File	Before	After
lib/index.js	38.2 kB	0.5%↑38.4 kB
lib/index.umd.cjs	18.5 kB	0.7%↑18.6 kB
lib/types/api/cart/index.d.ts	11.4 kB	1%↑11.5 kB
Total (Includes all files)	114.3 kB	0.4%↑114.8 kB
Tarball size	29.5 kB	0.4%↑29.6 kB

Unchanged files

File	Size
lib/api/cart.d.ts	4.6 kB
lib/api/customers.d.ts	1.3 kB
lib/api/orders.d.ts	782 B
lib/api/places.d.ts	1.3 kB
lib/api/resource.d.ts	1.3 kB
lib/api/template.d.ts	686 B
lib/clients/buyers.d.ts	236 B
lib/helpers/auth.d.ts	239 B
lib/helpers/cookies.d.ts	71 B
lib/helpers/datetime.d.ts	2.1 kB
lib/helpers/item.d.ts	3.2 kB
lib/helpers/location.d.ts	3.9 kB
lib/helpers/money.d.ts	1.5 kB
lib/index.d.ts	855 B
lib/types/api/cart/private.types.d.ts	778 B
lib/types/api/customers/index.d.ts	427 B
lib/types/api/orders/index.d.ts	346 B
lib/types/api/places/index.d.ts	1.9 kB
lib/types/api/resource/index.d.ts	4.1 kB
lib/types/api/resource/private.types.d.ts	60 B
lib/types/api/template/index.d.ts	808 B
lib/types/clients/buyers.private.d.ts	365 B
lib/types/helpers/datetime/index.d.ts	3.9 kB
lib/types/helpers/item/index.d.ts	3.1 kB
lib/types/helpers/location/index.d.ts	3.4 kB
lib/types/helpers/money/index.d.ts	92 B
lib/types/looseobject.d.ts	78 B
LICENSE	1.1 kB
package.json	2.1 kB
README.md	1.6 kB

_{🤖 This report was automatically generated by pkg-size-action}

[github-actions]

🎉 This PR is included in version 1.0.0-alpha.2 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀