Set up validation for all indicators

[sgsmob]

Indicators:

• [x] changehc
• [ ] claims_hosp
• [ ] doctor_visits
• [ ] fb_survey
• [x] google_symptoms
• [x] hhs_hosp
• [x] jhu (#752)
• [ ] nchs_mortality
• [x] quidel_covidtest
• [x] safegraph_patterns
• [x] usafacts

Inactive Indicators:

• cdc_covidnet
• combo_cases
• google_health
• hhs_facilities
• quidel
• safegraph

This should basically involve:

1. Set up bare-bones params.json that specifies:
   • global.data_source (the indicator name)
   • global.span_length = 14
   • dynamic.smoothed_signals
   • dynamic.max_expected_lag
   • dynamic.min_expected_lag
2. Get the indicator output by running it or downloading some cached files from somewhere
3. Run the validation from the indicator directory using python -m delphi_validation
4. Investigate the output and use it to tune the remaining validation parameters

[qx-teo]

Validation parameters have been added (and implemented) for all but one indicator ran using automation.

Exceptions include:

• nchs_mortality: Indicator provides weekly data, which requires modification of the validator (see #1117)
• cron indicators: doctor-visits, fb-survey, hospital-admissions, indicator-combination. Of all these, params.json.template files have been created, but validation isn't currently implemented in the pipeline yet.

[nmdefries]

Validation is rolled out to all daily signals in dry-run mode. Acquisition blocking is turned off because validation is too sensitive for it to be useful.