Include filesize when opening a file with searchpaths

src/ObjLoading/SearchPath/ISearchPath.cpp

@@ -0,0 +1,17 @@
+#include "ISearchPath.h"
+
+bool SearchPathOpenFile::IsOpen() const
+{
+    return m_stream != nullptr;
+}
+
+SearchPathOpenFile::SearchPathOpenFile()
+    : m_length(0)
+{
+}
+
+SearchPathOpenFile::SearchPathOpenFile(std::unique_ptr<std::istream> stream, const int64_t length)
+    : m_stream(std::move(stream)),
+      m_length(length)
+{
+}