Viewer: Finally fix Carousel navigation depending on URL

- Instead of detecting every case using popState event or whatnot, used a Sapper page stores subscribe to go to the current photo from the URL param (findIndex in photos)
- No page transition when navigating between photos in Viewer, but runs In and Out
- Also shortened dispatches to direct value over an object

src/routes/location/[country]/[place].svelte

@@ -80,7 +80,7 @@
     let paginatedPhotos = photos.filter(photo => photo.hidden === false)
 
     // Update pagination event from Pagination component
-    const updatePagination = event => paginatedPhotos = event.detail.paginatedPhotos
+    const updatePagination = event => paginatedPhotos = event.detail
 
 
     /*