mgr/dashboard: Replace font-awesome with fork-awesome

mgr/dashboard: Replace font-awesome with fork-awesome

Replaces the dependency on Font Awesome with Fork Awesome
(https://forkawesome.github.io/), which is a plug-in replacement
for font-awesome 4.7.0 and adds a few more icons (see
https://forkawesome.github.io/Fork-Awesome/whats-new/ for
background information about this fork).

It is licensed under the following licenses - see
https://forkawesome.github.io/Fork-Awesome/license/ for details:

Fonts: SIL OFL 1.1
Code: MIT License
Documentation: CC BY 3.0

Signed-off-by: Lenz Grimmer <lgrimmer@suse.com>