sls deploy with an apim in another resource group

[kevboutin]

Having the function app and APIM in separate resource groups would be very handy. We use a Premium APIM that spans multiple regions where we have multiple function apps in different resource groups.

How difficult would this change be?
I would assume we would need another property in the serverless yaml for the apim resource group name as well as some resulting ARM template changes to support this.