Integrate icon for French translation

[TheMarex]

#177 added French translations, this is not integrated into the frontend yet ~~since it is missing an icon to select the language.~~

This needs to be integrated in the menu displayed on project-osrm.org

[ymoisan]

Thanx ! I thought you might already have a flag to include in flags.svg. I'm really eager to have French directions :-)

[ymoisan]

See 3892090 for a French flag in SVG format.

[batpad]

The SVG for the French flag needs to be added here: https://github.com/Project-OSRM/osrm-frontend/blob/gh-pages/images/osrm.toolbar.icons.svg and then minor changes to the code to get it to work.

@bhousel ^ do you think you maybe able to help? I know nothing about Inkscape and SVG sprite generation - but if you can get the flag in there, I can take it from there. Thanks!

[daniel-j-h]

Flagging (heh): same needs to be done for all languages here still missing from the icons.

[batpad]

cc @ajithranka

[yuryleb]

French is on place after implementing select-based language chooser (#228)

[1ec5]

The flags are no longer used after #214, correct? Can we safely delete 🇺🇸 and 🇩🇪 from osrm.toolbar.icons.svg?