Add read_returns and write_returns to access scopes enums

[arsuceno]

Hi,

It could be possible to add read_returns and write_returns to AuthorizationScope enum? They are needed to manage returns https://shopify.dev/docs/apps/fulfillment/returns-apps/returns . Like this:

    [EnumMember(Value = "read_returns")]
    ReadReturns,

    [EnumMember(Value = "write_returns")]
    WriteReturns
    

I can do a PR for this. Thanks!

[nozzlegear]

Sure! If you want to do a pull request for this I’d be happy to merge and publish it.

[arsuceno]

Here we go https://github.com/nozzlegear/ShopifySharp/pull/1053