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.ts

@@ -63,6 +63,7 @@ export class InfiniteScrollerComponent implements OnInit, OnChanges, OnDestroy {
 
   @Input() goToPage: ReplaySubject<number> = new ReplaySubject<number>();
   @Input() bookmarkPage: ReplaySubject<number> = new ReplaySubject<number>();
+  @Input() fullscreenToggled: ReplaySubject<boolean> = new ReplaySubject<boolean>();
   
   /**
    * Stores and emits all the src urls
@@ -152,7 +153,8 @@ export class InfiniteScrollerComponent implements OnInit, OnChanges, OnDestroy {
   }
 
   ngOnInit(): void {
-    fromEvent(window, 'scroll')
+    const reader = document.querySelector('.reader') || window;
+    fromEvent(reader, 'scroll')
     .pipe(debounceTime(20), takeUntil(this.onDestroy)) 
     .subscribe((event) => this.handleScrollEvent(event));
 
@@ -183,6 +185,13 @@ export class InfiniteScrollerComponent implements OnInit, OnChanges, OnDestroy {
         }
       });
     }
+
+    if (this.fullscreenToggled) {
+      this.fullscreenToggled.pipe(takeUntil(this.onDestroy)).subscribe(isFullscreen => {
+        this.debugLog('[FullScreen] Fullscreen mode: ', isFullscreen);
+        this.setPageNum(this.pageNum, true);
+      });
+    }
   }
 
   /**