Fix demographic dropdown display text

[benhammondmusic]

Describe the bug

some of the newer demographic options display as snake_case rather than user-friendly casing in the dropdown select box

To Reproduce
Steps to reproduce the behavior:
0. Ensure the feature flag is enabled for cancer screening phrma brfss topics on your environment

1. Go to http://localhost:3000/exploredata?mls=1.gun_violence-3.cancer_screening-5.00&group1=All&demo=race_and_ethnicity&mlp=comparevars&group2=All
2. Click on sidebar dropdown "Demographic"
3. observe weirdly formatted disabled demo options

Expected behavior
User facing text should not look like variable names. e.g. we want Insurance Status not insurance_status

Screenshots

[vinhyan]

Hi! I can look into this issue :)