Reader Fixes (#951)

* Normalized paths on download controller and when scan is killed due to missing or empty folders, log a critical error.

* Tweaked the query for OnDeck to better promote recently added chapters in a series with read progress, but it's still not perfect.

* Fixed an issue where up/down key weren't working unless you clicked on the book explicitly

* Fixed an issue where infinite scroller was broken in fullscreen mode

* When toggling fullscreen mode on infinite scroller, the current page is retained as current position

* Fixed an issue where a double render would occur when we didn't need to render as fit split

* Stop showing loader when not using fit split

UI/Web/src/app/manga-reader/infinite-scroller/infinite-scroller.component.scss

@@ -25,6 +25,10 @@
     width: 100% !important;
 }
 
+// .img-container {
+//     overflow: auto;
+// }
+
 
 @keyframes move-up-down {
     0%, 100% {