Support unified location report

[Adam Winer]

User request:

A display of all potential birds, ones I have seen in Chile, ones I've seen elsewhere AND WHERE I've seen them. When I export a Chile spreadsheet, it does differentiate between SEEN in Chile, SEEN Elsewhere, and Potential lifers, but I haven't found a display within Scythebill where I can see all 3 categories (let alone where other than Chile I've seen that species.)

[Adam Winer]

A mostly-complete solution in 35df3a9 that makes it clear where in (say) Chile the species has been seen, so you can differentiate (in a single view) between birds that have been seen in Chile, seen elsewhere, and potential lifers. Still can't see where elsewhere you've seen the species, which is potentially relevant if you're concerned about splits, but I can't sanely display all of that (since you might have seen it in many other places - which would I show?)