win: enable PowerShell as TI runs #128 #412 #421

Refactor Windows scripts to run as TrustedInstaller using PowerShell
instead of batch files. This improves code reuse and enables more
complex logic for system modifications.

Key changes:

- Add function to run any PowerShell script as TrustedInstaller
- Refactor existing functions to use new TrustedInstaller capability
- Enable soft deletion of protected registry keys and files (#412).
- Resolve issues with renaming Defender files (#128).

Other supporting changes:

- Enhance service disabling to handle dependent services
- Use base64 encoding of 'privacy.sexy' to avoid Defender alerts (#421).
- Add comments to generated code for better documentation