Update flusurv schema and docs with new age, sex, and race groups

[nmdefries]

Summary:

Update flusurv table schema to support #1278. Also make sure rate_age_5, 6, and 7 are returned.

Necessary for #1247

Prerequisites:

• Unless it is a documentation hotfix it should be merged against the dev branch
• Branch is up-to-date with the branch to be merged with, i.e. dev
• Build is successful
• Code is cleaned up and formatted

[nmdefries]

@korlaxxalrok Tentatively tagging you for review. If you're not familiar with these files, let me know and I'll ask around for an alternative! :)

[melange396]

looks good, just a few optional things about repeated information across comments in various places

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[melange396]

looks good!

[melange396]

This got lost somehow... Im going to merge it now; I just need to remember to run the migration before release deployment!

[melange396]

aw crap, i wasnt paying attention and i thought this was going to merge into the dev branch... im going to try to revert it and revisit it again when i have a chance to review #1278

[melange396]

ugh, i made a mess. this PR's status can't be changed from "Merged". I will leave a note on #1278 that it needs to re-merge this (which is now probably best done by reverting #1426)