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/OSD/OSD_LocalFileSystem.hxx

@@ -0,0 +1,41 @@
+// Copyright (c) 2021 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _OSD_LocalFileSystem_HeaderFile
+#define _OSD_LocalFileSystem_HeaderFile
+
+#include <OSD_FileSystem.hxx>
+
+//! A file system opening local files (or files from mount systems).
+class OSD_LocalFileSystem : public OSD_FileSystem
+{
+  DEFINE_STANDARD_RTTIEXT(OSD_LocalFileSystem, OSD_FileSystem)
+public:
+
+  //! Constructor.
+  OSD_LocalFileSystem() {}
+
+  //! Returns TRUE if URL defines a supported protocol.
+  Standard_EXPORT virtual Standard_Boolean IsSupportedPath (const TCollection_AsciiString& theUrl) const Standard_OVERRIDE;
+
+  //! Returns TRUE if current input stream is opened for reading operations.
+  Standard_EXPORT virtual Standard_Boolean IsOpenIStream (const opencascade::std::shared_ptr<std::istream>& theStream) const Standard_OVERRIDE;
+
+  //! Opens stream buffer for specified file URL.
+  Standard_EXPORT virtual opencascade::std::shared_ptr<std::streambuf> OpenStreamBuffer
+                          (const TCollection_AsciiString& theUrl,
+                           const std::ios_base::openmode theMode,
+                           const int64_t theOffset = 0,
+                           int64_t* theOutBufSize = NULL) Standard_OVERRIDE;
+};
+#endif // _OSD_LocalFileSystem_HeaderFile