Add commit hash for the package tag and update package if the tagged release has changed in any way

[dbeatty10]

Feature

Add a new field for the commit hash for the package tag within data/packages/ORG_NAME/PACKAGE_NAME/versions/MAJOR.MINOR.PATCH.json.

Then determine if the hash has changed when looking for new package versions.

Alternatively, determine if the gzip SHA has changed.

In either case, update the package in the Hub if it has changed.

Context

If a package creates a tag initially and then updates it later, the hubcap script won't pick up the changes, more detail here:
dbt-labs/hub.getdbt.com#3842 (comment)

There might even be a very limited set of circumstances that it would even create any sort of problem, and the issue linked above might be the only one.

Workarounds

There are a couple workarounds that can be used in the meantime:

1. The package maintainer can tag a new release.
2. Manually making updates like Re-tagged package not picked up (brooklyn-data/dbt_artifacts) hub.getdbt.com#3842 when relevant.

Summary

I'm guessing we'll choose not to prioritize this work since it is rare and easy to overcome by the package maintainer making a new release.