This should be able to download any installer (.msi, .deb, .rpm, whatever) for any compass variant (regular, readonly, isolated).

Only for the just-packaged version of compass from this current evergreen version (ie. the one built by this PR or beta or ga release). This is for the tests that check that you can install compass and that you can upgrade from this version of compass.

Or for the most recent beta or ga release based on the download manifest. This is for testing that you can upgrade TO this version of compass.

Feel free to split this ticket into sub-tasks.