Migrate all mongodb-awesome-backup repo code/actions to this repo

[pdcp1]

Part of issue #3023

This PR moves the whole GitHub Actions code from mongodb-awesome-backup to this repo.
It also fixes the broken CSET CSV file export.

The following GitHub Action is added.

• .github/workflows/db-backup.yml

This action is responsible for generating the DB backup and DB snapshots.

New GitHub Actions environment secrets needed

These Cloudflare credentials must have write permissions

• secrets.CLOUDFLARE_R2_WRITE_ACCESS_KEY_ID
• secrets.CLOUDFLARE_R2_WRITE_SECRET_ACCESS_KEY

Testing

This code can be tested on Pablo's environment https://github.com/pdcp1/aiid/actions/workflows/db-backup.yml

Release considerations

Both GitHub Actions (Public backup to the cloud and Private backup to the cloud) on the original repo should be disabled as soon as we release this PR into Production.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.34%. Comparing base (64e1275) to head (a889f57).
Report is 1 commits behind head on staging.

Additional details and impacted files

@@             Coverage Diff             @@
##           staging    #3030      +/-   ##
===========================================
+ Coverage    79.25%   79.34%   +0.09%     
===========================================
  Files          165      165              
  Lines        13263    13263              
  Branches      1524     1525       +1     
===========================================
+ Hits         10511    10523      +12     
+ Misses        2459     2447      -12     
  Partials       293      293              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[pdcp1]

I'm taking my approval back because I'm noticing that we are not telling the workflow which environment it should get variables from (staging, production, etc.).

The environment input was added and it's ready for review

[smcgregor]

@pdcp1 Please ping me if/when I can retire the old repo.

[kepae]

Secrets updated!

[pdcp1]

@pdcp1 Please ping me if/when I can retire the old repo.

@smcgregor According to our Slack conversation, @kepae will be in charge of this repo deactivation.