Turn page while playing (#1383) fixes #1365

* Add an EReader setting for turning when playing

This allows to allow the navigation with the Volume buttons even when
audiobooks are playing.

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Co-authored-by: advplyr <advplyr@protonmail.com>

strings/de.json

@@ -179,9 +179,8 @@
   "LabelNarrator": "Erzähler",
   "LabelNarrators": "Erzähler",
   "LabelNavigateWithVolume": "Mit Lautstärke blättern",
-  "LabelNavigateWithVolumeDisabled": "Aus",
-  "LabelNavigateWithVolumeEnabled": "An",
   "LabelNavigateWithVolumeMirrored": "Umgekehrt",
+  "LabelNavigateWithVolumeWhilePlaying": "Auch bei Wiedergabe mit Lautstärketasten blättern",
   "LabelNever": "Nie",
   "LabelNewestAuthors": "Neueste Autoren",
   "LabelNewestEpisodes": "Neueste Episoden",
@@ -190,6 +189,7 @@
   "LabelNotStarted": "Nicht begonnen",
   "LabelNumEpisodes": "{0} Episoden",
   "LabelOff": "Aus",
+  "LabelOn": "An",
   "LabelPassword": "Passwort",
   "LabelPath": "Pfad",
   "LabelPlaybackDirect": "Direkt",