0032099: Visualization - define OSD_FileSystem class managing opening of file streams

1) Remove unnecessary includes of "Standard_OStream.hxx" file and add it only into files where it is really used.
2) Create the base interface for a file stream provider OSD_FileSystem and its inheritor OSD_CachedFileSystem that keeping last stream to be reused for opening a stream with the same URL.
3) Use OSD_CachedFileSystem object instead of RWGltf_GltfSharedIStream during Gltf reading.

src/Standard/Standard_CString.cxx

@@ -23,7 +23,6 @@
 #include <Standard_CLocaleSentry.hxx>
 #include <Standard_CString.hxx>
 #include <Standard_Type.hxx>
-#include <Standard_OStream.hxx>
 #include <string.h>
 #include <stdarg.h>
 

src/Standard/Standard_ExtCharacter.hxx

@@ -25,7 +25,6 @@
 #define _Standard_ExtCharacter_HeaderFile
 
 #include <Standard_TypeDef.hxx>
-#include <Standard_OStream.hxx>
 
 #include <string.h>
 

src/Standard/Standard_Mutex.cxx

@@ -14,7 +14,6 @@
 // commercial license or contractual agreement.
 
 #include <Standard_Mutex.hxx>
-#include <Standard_OStream.hxx>
 
 #include <errno.h>
 

src/Standard/Standard_Real.cxx

@@ -18,7 +18,6 @@
 #include <Standard_NumericError.hxx>
 #include <Standard_NullValue.hxx>
 #include <Standard_Stream.hxx>
-#include <Standard_OStream.hxx>
 
 static const Standard_Real ACosLimit = 1. + Epsilon(1.);
 

src/Standard/Standard_ShortReal.cxx

@@ -16,7 +16,6 @@
 #include <Standard_RangeError.hxx>
 #include <Standard_NullValue.hxx>
 #include <Standard_Stream.hxx>
-#include <Standard_OStream.hxx>
 
 //============================================================================
 // function : HashCode