1. Fix issue install-sshd.ps1 failed on Nano
2. Update settings of services in install-sshd.ps1 to match windows inbox
3. added setup tests and update the test helper scripts to run setup tests before changing configurations on the machine
4. added uninstallation tests
Regression: Service is unable to start if "ssh" programdata directory is missing.
Reason: This is due to refactored changes around w32_programdir() that moved its initialization to within win32_posix_initialize. sshd_main() is relying on this call even before the POSIX layer gets initialized.
Fix: Reverted the refactoring changes and added comments to consolidate these changes later. Also removed directory creation logic in install-sshd.ps1 that masked this issue before.
