Remove structured data from templates

[nickcernis]

As reported at https://wordpress.org/support/topic/structured-data-problem-using-this-plugin-and-woocommerce-3-x/, WooCommerce 3 switched to JSON LD for structured data.

https://github.com/woocommerce/woocommerce/wiki/2.6.x-to-3.0.0-Developer-Migration-Notes#product-schema-markup-moved-to-json-ld-format

The schema markup in our product templates therefore causes errors in Google's structured data testing tool, because WooCommerce 3 no longer outputs expected schema output in tags such as product headings:

Under Woo 2.6.14 the markup looked like this and was valid:

I suggest we drop the schema markup from product templates and make WooCommerce 3 the minimum recommended compatible version.

[nickcernis]

To test:

• Visit a product page.
• Copy the HTML source.
• Paste to https://search.google.com/structured-data/testing-tool/ and run Google's test.

Confirm:

• Product is detected, with correct data for the product.
• Product contains no errors or warnings, as below.

[nickcernis]

Confirmed ×1 in WP.org forums:

https://wordpress.org/support/topic/schema-error-3/#post-10478384

[swa433]

@nickcernis Confirmed +1
(product is detected, with correct data & without any error/warning related to product)

Environment:
WordPress:
Version: 4.9.7

PHP:
Versions: 5.6.24 & 7.1.14

Genesis Framework:
Version: 2.6.1

Genesis Sample (active theme):
Version: 2.6.0

WooCommerce:
Version: 3.4.3

Genesis Connect for WooCommerce:
Version: 0.9.10
Issue reproducible!

Genesis Connect for WooCommerce:
Version: 0.9.11 ( https://github.com/copyblogger/genesis-connect-woocommerce )
Issue fixed!