Feature: Store audit reports in a GCS bucket

[derekherman]

Summary

This PR stores the results of an audit (the report) in a Google Cloud Storage bucket, instead of Firestore. As well, dependencies have been updated for both development and live services. Test coverage remains at 100% but I will need to deploy and test this code on GCP before merging.

Checklist

• [x] My code is tested and passes existing tests.
• [x] My code follows the Tide Contributing Guide (updates are often made to the guidelines, check it out periodically).

[bartoszgadomski]

@jeffpaul @ivankruchkoff I tested this code on my localhost and I confirm that:

• it generate report files correctly and uploads them to associated storage bucket on /api/v1/audit/... endpoint hit
• it fetch files correctly and returns its values on /api/v1/report/... endpoint hit

Description	Screenshot / attachment
Response of /api/v1/audit/...
Content of Firebase storage bucket - lighthouse directory
Content of Firebase storage bucket - phpcs_phpcompatibilitywp directory
Content of lighthouse and phpcs_phpcompatibilitywp report files	reports.zip