feat(ui): add follow button, follows card, and inbox page

src/pages/SettingsPage.steam.test.jsx

@@ -32,6 +32,7 @@ function renderPage(me, {redirectUrl = STEAM_URL, entry = '/settings'} = {}) {
         'PUT /api/users/settings': noBody,
         'POST /api/auth/refresh': noBody,
         'GET /api/version': json(404, {}),
+        'GET /api/follows': json(200, {following: [], followers: []}),
     });
     renderWithProviders(<SettingsPage/>, {path: '/settings', entries: [entry]});
 }