Windows agent: report outdated Chocolatey packages

The Windows agent currently finds outdated software through WinGet and Windows Update. Software installed with Chocolatey isn't checked against Chocolatey's own feed, so Chocolatey-managed apps can be missed or reported inaccurately.

Request: when Chocolatey is installed, also collect choco outdated results so Chocolatey-managed packages show their available updates.

Originally raised on GitHub as #839.