#6915724 Show Jetpack end-user license in purchase section

Changes proposed in this Pull Request

• Include below the purchase metadata (owner, price, renewal, and payment method) the end-user license key related to the subscription.
• Rename the jetpack/user-licensing-m1 feature flag to jetpack/user-licensing.

Testing instructions

Prerequisites

• Access to a WPCOM sandbox.
• Add add_filter( 'jetpack_license_checkout_m2_enabled', '__return_true' ); to your 0-sandbox.php.
• Sandbox public-api.wordpress.com.

Instructions

• Download this PR.
• Start Calypso blue with yarn start.
• Make a standard Jetpack purchase.
• Go to http://calypso.localhost:3000/purchases/subscriptions/:site.
• Select the row that shows the subscription you just purchased.
• Verify that you see the license key associated with the subscription.
• Verify that if you click the Copy button, the license key is transferred to your clipboard.
• Verify that the UI looks fine on smaller viewports.
• Make sure these steps work for both plans and products.
• Verify that the UI has not changed for WPCOM plans (you can compare production against development to be sure).
• Verify that if there is no license key for the subscription, the app does not throw an error in the console or anywhere else (you can test this by “unsandboxing” public-api.wordpress.com).

Related to 1201096622142517-as-1201261928772896

Demo