#5529920 Move out store setup from extension/woocommerce to my-sites section

Changes proposed in this Pull Request

This PR moves the setup of WooCommerce for Atomic sites that do not yet have the WooCommerce plugin out extensions/woocommerce to a standalone page in located under my-sites.

The new section can be accessed via https://wordpress.com/woocommerce/{site}. In order to support Nav Unification, the actual link to the new woocommerce section from sidebar should be addressed in wpcomsh repository.

Fixes #49424.

Testing instructions

• Start calypso in local.
• Create a new business plan site (Alternatively, you can also disable WooCommerce plugin in an existing business site).
• If site is not yet Atomic, go to plugins, and install any plugin other than WooCommerce to convert site to Atomic.
• In the site’s URL, replace home with woocommerce.
• Click on “Setup my store”.
• Observe the progress and page should redirect to first step of WooCommerce onboarding wizard.
• For tracks, calypso_woocommerce_dashboard_action_click should be called with { action: 'initial-setup' } when setup is run.

Demo