Add script offset / delay to Handy support. (#1573)

* Add script offset / delay to Handy support.

Further work on  #1376.

Offsets are added to the current video position, so a positive value leads to earlier motion.  (The most common setting.)

This is needed because most script times have a consistent delay when compared to the video. (Delay from the API calls to the server should be handled by the server offset calculation.)

* Rename scriptOffset to funscriptOffset
* Correct localisation keys

Co-authored-by: WithoutPants <53250216+WithoutPants@users.noreply.github.com>

graphql/documents/data/config.graphql

@@ -56,6 +56,7 @@ fragment ConfigInterfaceData on ConfigInterfaceResult {
   language
   slideshowDelay
   handyKey
+  funscriptOffset
 }
 
 fragment ConfigDLNAData on ConfigDLNAResult {