Replace device with session in UI text

This replaces "device" with "session" throughout user-visible text at the React
layer. Variable names and comments are left as-is for now.

src/components/views/settings/tabs/user/GeneralUserSettingsTab.js

@@ -261,7 +261,7 @@ export default class GeneralUserSettingsTab extends React.Component {
             title: _t("Success"),
             description: _t(
                 "Your password was successfully changed. You will not receive " +
-                "push notifications on other devices until you log back in to them",
+                "push notifications on other sessions until you log back in to them",
             ) + ".",
         });
     };