Release testing instructions: Storefront 3.3.0

Check if WC Admin inbox is available before using it (#1583)

WC up to date

1. Edit your DB options table and delete the storefront_nux_dismissed option value, or use a clean install.
2. Activate Storefront.
3. Verify a notice is added to the WC Admin inbox.

WC disabled

1. Disable WC admin using the filter: add_filter( 'woocommerce_admin_disabled', '__return_true' );
2. Edit your DB options table and delete the storefront_nux_dismissed option value, or use a clean install.
3. Activate Storefront.
4. Verify the old style admin notice instead of a fatal error.

Old WooCommerce

1. Install a WC version prior to 4.8.
2. Edit your DB options table and delete the storefront_nux_dismissed option value, or use a clean install.
3. Activate Storefront.
4. Verify the old style admin notice instead of a fatal error.

Use proper escape functions in several templates (#1581)

1. Go to Settings > Discussion and set the Break comments into pages with option to 5. Then, add 6 comments to a post. Verify: the aria-label of #comment-nav-above has text.
2. In Appearance > Customize > Menus add a new menu to the secondary menu and publish it. Verify: the aria-label of .secondary-navigation has text.
3. In a new site, install WooCommerce and activate it. After that, install Storefront. (Otherwise, in an existing install set storefront_nux_dismissed option to 0). Go to Appearance > Storefront. Verify. the Skip button is displayed correctly.

To test for regressions please refer to Testing Storefront: flows and features.