Move from google assets to own assets

[David]

Currently, the font Roboto as well as the material icons are imported from google API (

damap-frontend/apps/damap-frontend/src/index.html

Lines 8 to 13 in 6e84345

 <link 
   href="https://fonts.googleapis.com/css?family=Roboto:300,400,500&display=swap" 
   rel="stylesheet" /> 
 <link 
   href="https://fonts.googleapis.com/icon?family=Material+Icons" 
   rel="stylesheet" /> 

).

These links will lead to a request (containing user-agent information) to the google API, which may be undesired by users.
It may also require a note and explicit consent from the user to perform such a request.

Instead, fonts and icons may be served as static assets from the application itself.