Update GraphQL queries to use aliases

[jcrichlake]

Summary

We are currently exporting the graphQL data as is from Github and transforming the column names in our python code to match what the database expects. We should instead use an alias in the GraphQL queries which would allow us to avoid transforms in the python code.

Acceptance criteria

Data columns from GraphQL are retrieved with the proper headings and the column name transformations are no longer needed.