Downloads page enhancements

The downloads page is getting longer with new additional links added to it. in order to avoid overwhelming users that are looking for a specific download link UXD suggestion is: 

1. Avoid long lists in each category. Show only the most common links and add a "Show more" option for less common downloads links (for example downloads that are relevant only for specific add-ons/ operators.) https://marvelapp.com/prototype/c7dehh1/screen/81511455 
2. In the installer list for OpenShift, show a dropdown for the platform type. https://marvelapp.com/prototype/c7dehh1/screen/81368889 

Out of Scope:

1. Consider adding additional filtering such as search, platform type, etc. (TBD)
2. Show a unique URL per line, for users who are led to the downloads page from an external source, each link should lead the user to the exact category/ download line.  Currently, expanding a row does update the URL.  May need to find tune URL query params to also include platform, os, and arch types.