feat(library): show set total playtime on dashboard cards

Most played and currently playing cards show the total playtime of
the game set. Use the own minutes when the API sends no total.

src/components/CurrentlyPlayingCard.test.jsx

@@ -0,0 +1,18 @@
+// @vitest-environment jsdom
+import {afterEach, describe, expect, it, vi} from 'vitest';
+import {cleanup, render, screen} from '@testing-library/react';
+import {MemoryRouter} from 'react-router-dom';
+import CurrentlyPlayingCard from './CurrentlyPlayingCard.jsx';
+
+vi.mock('react-i18next', () => import('../test/i18n-mock.js'));
+
+describe('CurrentlyPlayingCard', () => {
+    afterEach(cleanup);
+
+    it('shows the set total of a game, not the minutes of its own row', () => {
+        render(<MemoryRouter><CurrentlyPlayingCard games={[{appid: 620, name: 'Portal 2', playtimeMinutes: 100,
+            totalPlaytimeMinutes: 600, status: 'PLAYING'}]}/></MemoryRouter>);
+
+        expect(screen.getByText('10h')).toBeTruthy();
+    });
+});