[enh] ES settings: allow to define a google API key, for address resolution in maps

www/index.html

www/js/config.js

www/plugins/es/js/services/geo-services.js

www/plugins/es/js/services/settings-services.js

www/plugins/es/templates/settings/plugin_settings.html

www/plugins/map/i18n/locale-fr-FR.json

www/plugins/map/js/controllers/settings-controllers.js

www/plugins/map/js/controllers/wot-controllers.js

www/plugins/map/js/plugin.js

www/plugins/map/js/services/wot-services.js

www/plugins/map/templates/network/view_map.html

www/plugins/map/templates/settings/es_settings_extend.html

www/plugins/map/templates/wot/popup_marker.html

www/plugins/map/templates/wot/view_map.html