feat(import): add the import page, multi-select add and the favorite platform

src/pages/GameLibrary.test.jsx

@@ -184,6 +184,15 @@ describe('GameLibrary with games added by hand', () => {
         expect(document.querySelector('img[src="https://images.igdb.com/z.jpg"]')).toBeTruthy();
     });
 
+    it('shows Steam as the platform of a Steam game, and links the import', async () => {
+        globalThis.fetch = answer([{appid: 220, name: 'Half-Life 2', playtimeMinutes: 0, status: 'BACKLOG', source: 'STEAM',
+            platform: null}], true);
+        renderLibrary();
+
+        expect(await screen.findByText('Steam')).toBeTruthy();
+        expect(screen.getByRole('link', {name: 'IMPORT.OPEN'}).getAttribute('href')).toBe('/import');
+    });
+
     it('hides the Steam sync for a user without a Steam ID but still offers adding a game', async () => {
         globalThis.fetch = answer([zelda], false);
         renderLibrary();