[DISCO-3256] chore(ci): migrate the "upload-test-artifacts" and "upload-coverage-artifacts" steps from CircleCI to GH Actions

[Trinaa]

References

JIRA: DISCO-3256

Description

• add a reusable workflow 'Upload to GCS' to GitHub actions
• incorporate 'Upload to GCS' in main-workflow GitHub action
• remove uploading test artifacts from CircleCI workflows
• update documentation

Tests

In order to make sure the new action will behave as expected, the following tests were conducted:

1. Tests Pass, Uploads in main-workflow only (Base Case) - PASS
2. Tests Pass, Upload result and coverage artifacts with filters to GCS -TODO
3. Tests Pass, Upload artifacts without filters to GCS -TODO
4. Tests Pass, No Artifacts -TODO
5. Tests Fail, Uploads result and coverage artifacts with filters to GCS -TODO

PR Review Checklist

Put an x in the boxes that apply

• This PR conforms to the Contribution Guidelines
• The PR title starts with the JIRA issue reference, format example [DISCO-####], and has the same title (if applicable)
• [load test: (abort|skip|warn)] keywords are applied to the last commit message (if applicable)
• Documentation has been updated (if applicable)
• Functional and performance test coverage has been expanded and maintained (if applicable)