Store Editing Templates: Add E2E tests for Product Tag block template

[tjcafferkey]

Scenario to cover:

• Should a user navigate to Site Editor > All Templates with an FSE theme active they should see the WooCommerce provided Product Tag block template.
• Should a user load the Product Tag template, the editor will have the “WooCommerce Product Grid Block” Legacy Template block present.
• Should a user load a product tag page on the frontend, it will render a list of products.
• Should a user customise the Product Tag template and save it. The user should see a "Clear customizations" option on the All Templates view (clearing customisations functionality should be covered by Gutenberg)
• Should a user load the customised Product Tag template the Site Editor should render these customisations
• Should a user have a customised Product Tag template, these customisations would be present on the frontend.