Return online and offline tokens in a single call

[uurcank]

Many apps support multiple user accounts, but they still need to make calls to the store in the background using an offline token.

Shopify's Oauth requires two separate calls to obtain different tokens.
This is an issue that prolongs the authentication for many Shopify apps and negatively impact merchant experience.

If the user has the required permissions, the callback can include the offline token as well as the online token. This way apps can get all the information in a single call. This will reduce the auth time significantly.

[uurcank]

@mkevinosullivan just a heads up. Is there anything in the roadmap to fix this issue?