Wrap up `PartisanFeelingThermometerUS` implementation

[JamesPHoughton]

This survey is based on descriptions in this issue: https://github.com/Watts-Lab/surveys/issues/109

There a few things missing:

• [ ] the scoring function is empty. We should look to the source lit referenced in the above issue to see how others have scored these (possibly a net difference between the two parties, or similar) and decide what we want to include in addition to the raw scores.
• [ ] Check the randomization and record the order that questions were administered
• [ ] Update the cypress test to actually check the values. (probably requires clicking on the bar in different locations...)

[JamesPHoughton]

pushing to GH, PR soon putting both raw values and absolute value of the difference in the output object, normalized to 0-1 scale