Bundle (Google) fonts for GDPR compliancy

[jmechnich]

Currently, the fonts Arvo and Lato are loaded from Google and are used primarily for installation, error and admin pages, if I am reading things correctly. As the useInternalAssets flags has been reenabled in c763d3e in order to load a local copy of jQuery, it would be great if we could do the same for the fonts.

References to the Google APIs for fonts exist in the following files:

admin/themes/default/common/header.php
admin/themes/default/common/login-header.php
admin/themes/default/upgrade/index.php
admin/themes/default/upgrade/migrate.php
application/views/scripts/error/index.php
application/views/scripts/functions.php
install/index.html
install/views/scripts/layout.phtml

As both fonts are covered by the OFL, there should not be any legal reason not to bundle them with Omeka.