Add opt-in data collection to Duplicate Post

[BobBreukhoven]

https://yoast.atlassian.net/browse/DUPP-69

As a product Owner I like to get tracking data from a position of the Duplicate Post Plugins users in order to have a better view of how they “profile” against our other known user groups.

Will probably be a mini-epic.

Needs decisions from Product and design from UX.

Maybe combine with DUPP-70: Add a "Installation Successful" Screen to Duplicate PostTO DO