[FEATURE]Headless (graphql) support

[indykoning]

Please rephrase the following line:

As a developer of a headless Magento implementation I'd like to be able to use postnl shipping methods using GraphQL in order to implement the postnl payment method with timeframes in the checkout.

Suggestions and background

Currently there is no way to implement the postnl shipping methods in a headless checkout based on graphql (which will be most usecases)

For timeframes this could be done either using a separate graphql query, or embedding the timeframes with the shipping method query as we already have access to the shipping address.

For setting the timeframe on the cart this could be added to the setShippingMethodsOnCart mutation

[JorisPostNL]

@indykoning Thank you for your suggestion, it has been added to our backlog and we will consider implementing it in the future.

Kind regards
Joris - PostNL