Duplicate footnotes when using footnote summary in metatag

Okay this solves it in my testing. The old Group code I took from the patches when that functionality was originally created, but it was far too difficult to read and follow the logic. This now is at least a bit more readable without changing the structure and allowed me to find duplicates based on the text, yet still keep the references unique for back-links. Let's see if the tests flag any regressions, otherwise I'll get a test added for this.

Automatically closed - issue fixed for 2 weeks with no activity.