Feature/reader skip duplicate chapters (#262)

* Skip duplicate chapters in the Reader

* Debounce "end of page" handling in the reader

* Update keyboard event listener

In case the "go" function changed, the listeners have to be updated

src/typings.ts

@@ -202,9 +202,15 @@ export interface IReaderSettings {
     staticNav: boolean;
     showPageNumber: boolean;
     loadNextOnEnding: boolean;
+    skipDupChapters: boolean;
     readerType: ReaderType;
 }
 
+export enum ChapterOffset {
+    PREV = -1,
+    NEXT = 1,
+}
+
 export interface ISearchSettings {
     ignoreFilters: boolean;
 }