Add script for customer deployments

[mattgauntseo-sentry]

I noticed that s4s has slightly differently migration steps for s4s and ST deployments.

This PR moves the container name / service name to an environment variable so we can re-use the migrate-reverse script on all regions and then there is a second script for the ST deployments migration.

Hopefully in the future we can merge the migration scripts, but this is the safest approach to avoid breaking things for now.

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: -2.08 ⚠️

Comparison is base (ce7bc50) 92.43% compared to head (906ed41) 90.35%.

❗ Current head 906ed41 differs from pull request most recent head 0f12c18. Consider uploading reports for the commit 0f12c18 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4438      +/-   ##
==========================================
- Coverage   92.43%   90.35%   -2.08%     
==========================================
  Files         769      804      +35     
  Lines       38218    39568    +1350     
  Branches        0      245     +245     
==========================================
+ Hits        35326    35751     +425     
- Misses       2892     3785     +893     
- Partials        0       32      +32     

see 44 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.