Create pivot view for multi-variable requests

[mkrisch]

When requesting multiple variables or multiple years for a given geography, it would be great to supply the years and variables as their own columns as opposed to their own rows. We use autocensus in class, but it requires some gymnastics to get the data into a single row (https://colab.research.google.com/drive/12qzwu6MQPpv5RLk0vs0SjEY-OvbivNc0?usp=sharing).

[cmsetzer]

@mkrisch, thanks for the suggestion (and the code example). I agree, having an easy way to produce "wide" ACS data would be useful. Maybe an optional parameter like Query(..., format='wide').

There are some design decisions and edge cases we'd need to think over, like how to report annotated values (link) in the wide format.

We'll plan to spend some time looking into this, and will leave this issue open in the meantime. Thanks!