chore: add abstraction for opening output files to be able to mock it

src/ObjCommon/SearchPath/IOutputPath.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <memory>
+#include <ostream>
+#include <string>
+
+class IOutputPath
+{
+public:
+    IOutputPath() = default;
+    virtual ~IOutputPath() = default;
+    IOutputPath(const IOutputPath& other) = default;
+    IOutputPath(IOutputPath&& other) noexcept = default;
+    IOutputPath& operator=(const IOutputPath& other) = default;
+    IOutputPath& operator=(IOutputPath&& other) noexcept = default;
+
+    virtual std::unique_ptr<std::ostream> Open(const std::string& fileName) = 0;
+};