Test: Add/remove system package

This PR covers issue #410 completely. 

I updated and seperated out the `add-package` and `add-package-group` functions. The intent was to remove the sleep statement `(Thread/sleep 50000)` and to monitor the package install/remove status effectively.

Also added a fn  `validate-package-info` to validate the package install/remove info page. Will add the similar implementation for package-groups, if this change looks okay.