DSUtil: Cosmetics.
Avoid the OSD flashing when skipping to a chapter.

The OSD displayed the seek message before it was immediately replaced by the chapter information.
Use elapsed/remaining time for the chapter change OSD depending on what is selected.

This commit fixes #1555.
AppSettings: migrate only present keys
Cosmetics in CAppSettings::UpdateSettings()
Fixes to reset settings option

 - Reset .ini now doesn't write ExePath to the registry
 - Reset .ini is now achieved through file write not delete

Fixes #3591
Cosmetic for chapter navigate skip.

Fixes CID #965888