SCUMM: Remove unsued method loadThumbnailFromSlot(int slot).
SCUMM: Slight cleanup in savegame code.
SCUMM: Slight cleanup in detection.cpp.
SCUMM: Cleanup querySaveMetaInfos implementation.

This results in less code and also less I/O operations (including seeking).
SCUMM: Small formatting fix.
GRAPHICS: Fix SharedPtrSurfaceDeleter for nullptr inputs.
DEVTOOLS: Include 'iterator' for std::back_inserter.
TSAGE: Fix savegame issue
FULLPIPE: Implement sceneHandler04_sub3()
FULLPIPE: Give some names in scene04
TSAGE: Fix for R2R maze minimap not handling right-hand column scrolling on-screen
TSAGE: R2R minimap scrolling fix applies vertically as well
TSAGE: R2R fix for zoomed speaking characters appearing correctly
FULLPIPE: Fix crash at scene03 load
FULLPIPE: Skip reading empty filenames
FULLPIPE: Fix crash at scene04 start
FULLPIPE: Implement  scene04_speakerCallback()
FULLPIPE: Some renames in scene04
FULLPIPE: Implement sceneHandler04_dropBottle()
FULLPIPE: Fix warning