Adapt Validator for Weekly Data

[qx-teo]

Summary
Validator currently only works on daily data, which means that it cannot be organically ran on sources like nchs-mortality.

Possible Solutions

• Releasing a version of the validator that only does checks unaffected by the weekly nature of the data (e.g. checking for missing date files, missing geo-type signal-type combinations) - will still need to tweak checks (e.g. making check_missing_dates only check for the first date of an epiweek)
• Adapting parameters to consider the last N data-points (a.k.a weeks) rather than the last N days (Issues with this: Using data from 14 weeks ago as a reference may not work as well in determining things like outliers or trends)

[qx-teo]

Working notes for this: https://docs.google.com/document/d/1hJ9M4gRepXS-WhGGLIxEuGYW6076cjSJ/edit?usp=sharing&ouid=109202993374473482519&rtpof=true&sd=true

[nmdefries]

Address #2023 first.