GHT "exploration path" to URL

[Ambrevar]

Is your feature request related to a problem? Please describe.

We've discussed Global History Tree features many times in the past, and one of the perks it gives us is the ability to remember the path that led to a specific link.

Today I found myself revisiting a page and I was wondering what had led me there in the first place. Then I realized it's a question I ask myself very often.

Retracing the exploration path is a very valuable refresher.

Describe the solution you'd like

Given a URL, display the list of parents or the whole history tree.

It's trivial to implement considering we already have buffer-history-tree.