win,msi: highlight installation of 3rd-party tools

Currently, the installation wizard more or less silently installs
third-party software (Boxstarter + Chocolatey). This adds some text
to the MSI installation dialog and to the Boxstarter installation
script.

PR-URL: https://github.com/nodejs/node/pull/23003
Refs: https://github.com/nodejs/node/pull/22645
Refs: https://github.com/nodejs/node/pull/22988


Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: João Reis <reis@janeasystems.com>