DEV-35179 (part2) improve Keyboard shortcut indicators, using native Mac symbols

indra/newview/skins/default/xui/da/notifications.xml

indra/newview/skins/default/xui/da/strings.xml

indra/newview/skins/default/xui/de/notifications.xml

indra/newview/skins/default/xui/de/strings.xml

indra/newview/skins/default/xui/en/notifications.xml

indra/newview/skins/default/xui/en/strings.xml

indra/newview/skins/default/xui/es/notifications.xml

indra/newview/skins/default/xui/es/strings.xml

indra/newview/skins/default/xui/fr/notifications.xml

indra/newview/skins/default/xui/fr/strings.xml

indra/newview/skins/default/xui/it/notifications.xml

indra/newview/skins/default/xui/it/strings.xml

indra/newview/skins/default/xui/ja/notifications.xml

indra/newview/skins/default/xui/ja/strings.xml

indra/newview/skins/default/xui/nl/notifications.xml

indra/newview/skins/default/xui/nl/strings.xml

indra/newview/skins/default/xui/pl/notifications.xml

indra/newview/skins/default/xui/pl/strings.xml

indra/newview/skins/default/xui/pt/notifications.xml

indra/newview/skins/default/xui/pt/strings.xml