UICommon/GameFile: std::move std::string argument in constructor

Allows for calling code to move the argument into the constructor,
avoiding a copy.

Source/Core/UICommon/GameFile.cpp

@@ -113,7 +113,7 @@ GameFile::LookupUsingConfigLanguage(const std::map<DiscIO::Language, std::string
 
 GameFile::GameFile() = default;
 
-GameFile::GameFile(const std::string& path) : m_file_path(path)
+GameFile::GameFile(std::string path) : m_file_path(std::move(path))
 {
   {
     std::string name, extension;

Source/Core/UICommon/GameFile.h

@@ -45,7 +45,7 @@ class GameFile final
 {
 public:
   GameFile();
-  explicit GameFile(const std::string& path);
+  explicit GameFile(std::string path);
   ~GameFile();
 
   bool IsValid() const;