Reduce the number of copies of Font Awesome that get bundled

The USGS Drupal template includes six different file formats of the Font Awesome icon font so that different browsers can use whichever format they support. However, Angular bundles all of these into the library and eventually the application, so users end up downloading all six, massively inflating the bundle size.

WOFF2 is the smallest of the formats and is supported by all modern browsers (certainly by everything in our .browserslistrc, which was the Angular default), so we could edit the Drupal template's common.css to only use that one format, which would significantly decrease the size of application bundles.

I built the example application without and with this change, and it reduced the initial bundle from 2.49 MB to 891.40 kB.