Forge `addon-install` should POST to the website REST services to update download count statistics

The website should be able to track download statistics for addons, as well as daily usage statistics. This should be built in to the addon-install command (if user has agreed to send stats.)

The addon-install command should post that an addon has been installed, and provide its maven coordinates, addon-id, the source repo if available, and any other information that can be extracted during installation.

Stats will only appear publicly if the addon is listed on the website. Otherwise stats will be held privately in confidence.