Improve performance of Webui::Packages::BinariesController#show

[hellcp-work]

Issue Description

It takes a while to fetch binary data from the backend, especially for instances using interconnect. In some instances rendering also takes a long time. We should defer some loading to after the page is already there.

Expected Result

The page loads much faster

How to Reproduce

1. Visit https://build.opensuse.org/projects/openSUSE:Factory/packages/kernel-default-base/repositories/standard/binaries
2. Click on Details link next to the largest file

Firefox reports it as: load: 1.20 min, we should be aiming for 3 seconds to page load and then content can load for as long as it wants when the page is loaded