Consolidate modern management scripts into DAT

[cmendesvdl]

Summary

• make DAT the maintained home for the ConfigMgr driver/BIOS package selectors
• add the Dell, HP, Lenovo, and Microsoft BIOS apply scripts with MIT attribution
• integrate the maintained standalone regression suites
• implement the advertised ConfigMgr hierarchy SiteCode/MDMSiteCode filter
• preserve DAT certificate pinning and Zip Slip-safe extraction
• expand the integrity manifest from 16 to 20 files

Validation

• all 8 PowerShell regression harnesses pass
• all PowerShell files parse under Windows PowerShell 5.1
• 20/20 manifest entries match exact bytes
• git diff --check passes

The standalone repositories are intentionally not deleted by this PR.