replace the python covidcast client in validator

[melange396]

Similar to #1931, the python covidcast client (which has some issues) is used in the delphi_utils.validator submodule and it can should come out of there:

• covidcast-indicators/_delphi_utils_python/delphi_utils/validator/run.py

  Line 8 in a6ea003

  import covidcast

• covidcast-indicators/_delphi_utils_python/delphi_utils/validator/datafetcher.py

  Line 12 in a6ea003

  import covidcast

• covidcast-indicators/_delphi_utils_python/delphi_utils/validator/dynamic.py

  Line 8 in a6ea003

  import covidcast

[melange396]

One interesting quirk of the covidcast client is that it pins "pandas<2", which nets version 1.5.3 (from ~1.5y ago)...

I find no reason/rationale for this in either the source or comments of cmu-delphi/covidcast#618 where the change was made :(

This also means that anything that imports the delphi_utils package inherits the version restriction.

The current version of Pandas is 2.2.2 -- which might offer significant performance improvements, but it risks breaking any number of things. Pandas is not pinned anywhere in this repo (except for the now-toothless spec in delphi_utils to >=1.1.0), so completing this issue may require changes or pinning in individual indicator code. EDIT: version pinning issue #1967 may be relevant for this.

[melange396]

#1985 is an effective stop-gap for removing the dependency implications (and it also partially fulfills #1931 and #1987 ), but it doesnt address the covidcast client inefficiencies mentioned in #1931...

to properly satisfy that , i think it should be sufficient to:

• replace these two calls with their one-line implementation :

  • covidcast-indicators/_delphi_utils_python/delphi_utils/validator/dynamic.py

    Line 82 in 1526dc9

    covidcast.use_api_key(self.params.api_key)

  • covidcast-indicators/_delphi_utils_python/delphi_utils/validator/run.py

    Line 21 in 1526dc9

    covidcast.use_api_key(params["validation"]["common"]["api_credentials"])

  • (in fact, it only necessary to use one of them to set the key, so the other can be removed)
• replace these two w/ calls to the delphi_epidata client and some data massaging:

  • covidcast-indicators/_delphi_utils_python/delphi_utils/validator/datafetcher.py

    Line 118 in 1526dc9

    meta = covidcast.metadata()

  • covidcast-indicators/_delphi_utils_python/delphi_utils/validator/datafetcher.py

    Lines 163 to 164 in 1526dc9

    	api_df = covidcast.signal(
    	data_source, signal_type, start_date, end_date, geo_type)

• remove covidcast from the delphi_utils dependencies
• add the covidcast client as a dependency for the sircal and google-symptoms packages
• pin pandas to v1.5.3 in the other packages found in this repo until we can explore what the ramifications will be for that upgrade
• (of course) fix tests