Local CSS and font files

Currently the software uses a custom mdl style css, which is downloaded from Google's storage. Also some custom font is downloaded from Google's font distribution site. At least the latter includes some url, which also points to Google.

I would like to get rid of resources, which get repeatedly from external sources. I already moved the javascript files into our repository. The mentioned files remain as I don't know where to retrieve a local-only version of them.