win: improve registry/recent cleaning

This commit introduces a new shared function to centralize all usages of
`reg delete .. /va`. The new function generates comments in code and can
recurse through subkeys. This enhances maintainability and reliability
by avoiding potential misuse or syntax errors.

Key changes:

- Add `ClearRegistryValues` function
- Update scripts to use the new function
- Add ability to recurse subkeys for registry value deletion, addressing
  issues where desired data was not deleted.

Other supporting changes:

- Improve documentation of the changed scripts.
- Add missing registry paths in scripts.
- Change value removal to value/subkey removal for correct behavior.
- Remove removal of undocumented keys.
- Rename related scripts for clarity.
- Adjust script recommendations.