Resource Group scoped cost exports from Azure on MCA accounts have different field names than expected when we process data. These field names are legacy field names that should be mapped to expected fields for when we process data. 

We have a similar process already in AWS where we remap column names as needed: https://github.com/project-koku/koku/blob/main/koku/masu/util/aws/aws_post_processor.py#L243-L246 

Legacy to current field mappings: https://learn.microsoft.com/en-us/azure/cost-management-billing/automate/migrate-consumption-usage-details-api#microsoft-customer-agreement-field-mapping