Update GHES generate script to accept `--use-github-storage` option

[begonaguereca]

Summary

Things happening in this PR:

1. Add --use-github-storage to the GenerateScript command
2. Update integration tests to use --use-github-storage command

Take it for a 🚗

export GH_PAT=<<PAT>> 

dotnet run --project src/gei/gei.csproj -- generate-script --github-source-org valet-testing --github-target-org octoshift-staging --use-github-storage true --ghes-api-url https://octoshift-ghe.westus2.cloudapp.azure.com/api/v3

• [x] Did you write/update appropriate tests
• [ ] Release notes updated (if appropriate)
• [ ] Appropriate logging output
• [ ] Issue linked
• [ ] Docs updated (or issue created)
• [ ] New package licenses are added to ThirdPartyNotices.txt (if applicable)

[github-actions[bot]]

Unit Test Results

829 tests   829 ✅  23s ⏱️   1 suites    0 💤   1 files      0 ❌

Results for commit f4e0d8b6.

:recycle: This comment has been updated with latest results.

[github-actions[bot]]

Package	Line Rate	Branch Rate	Complexity	Health
gei	80%	71%	550	✔
ado2gh	84%	78%	627	✔
Octoshift	87%	76%	1298	✔
bbs2gh	79%	74%	666	✔
Summary	83% (7022 / 8410)	75% (1579 / 2098)	3141	✔