VideoCommon/OnScreenDisplay: Take Message's std::string parameter by value

Allows callers to std::move strings into the functions (or automatically
assume the move constructor/move assignment operator for rvalue
references, potentially avoiding copies altogether.

Source/Core/Core/Core.cpp

@@ -150,7 +150,7 @@ std::string StopMessage(bool main_thread, const std::string& message)
                           Common::CurrentThreadId(), message.c_str());
 }
 
-void DisplayMessage(const std::string& message, int time_in_ms)
+void DisplayMessage(std::string message, int time_in_ms)
 {
   if (!IsRunning())
     return;
@@ -162,8 +162,8 @@ void DisplayMessage(const std::string& message, int time_in_ms)
       return;
   }
 
-  OSD::AddMessage(message, time_in_ms);
   Host_UpdateTitle(message);
+  OSD::AddMessage(std::move(message), time_in_ms);
 }
 
 bool IsRunning()

Source/Core/Core/Core.h

@@ -63,7 +63,7 @@ void SaveScreenShot(const std::string& name, bool wait_for_completion = false);
 void Callback_WiimoteInterruptChannel(int number, u16 channel_id, const u8* data, u32 size);
 
 // This displays messages in a user-visible way.
-void DisplayMessage(const std::string& message, int time_in_ms);
+void DisplayMessage(std::string message, int time_in_ms);
 
 void FrameUpdateOnCPUThread();
 void OnFrameEnd();

Source/Core/Core/DSP/DSPHost.h

@@ -17,7 +17,7 @@ namespace DSP::Host
 {
 u8 ReadHostMemory(u32 addr);
 void WriteHostMemory(u8 value, u32 addr);
-void OSD_AddMessage(const std::string& str, u32 ms);
+void OSD_AddMessage(std::string str, u32 ms);
 bool OnThread();
 bool IsWiiHost();
 void InterruptRequest();

Source/Core/Core/HW/DSPLLE/DSPHost.cpp

@@ -36,9 +36,9 @@ void WriteHostMemory(u8 value, u32 addr)
   DSP::WriteARAM(value, addr);
 }
 
-void OSD_AddMessage(const std::string& str, u32 ms)
+void OSD_AddMessage(std::string str, u32 ms)
 {
-  OSD::AddMessage(str, ms);
+  OSD::AddMessage(std::move(str), ms);
 }
 
 bool OnThread()

Source/Core/VideoCommon/OnScreenDisplay.cpp

@@ -27,8 +27,8 @@ constexpr float WINDOW_PADDING = 4.0f;  // Pixels between subsequent OSD message
 struct Message
 {
   Message() = default;
-  Message(const std::string& text_, u32 timestamp_, u32 color_)
-      : text(text_), timestamp(timestamp_), color(color_)
+  Message(std::string text_, u32 timestamp_, u32 color_)
+      : text(std::move(text_)), timestamp(timestamp_), color(color_)
   {
   }
   std::string text;
@@ -79,18 +79,18 @@ static float DrawMessage(int index, const Message& msg, const ImVec2& position,
   return window_height;
 }
 
-void AddTypedMessage(MessageType type, const std::string& message, u32 ms, u32 rgba)
+void AddTypedMessage(MessageType type, std::string message, u32 ms, u32 rgba)
 {
   std::lock_guard<std::mutex> lock(s_messages_mutex);
   s_messages.erase(type);
-  s_messages.emplace(type, Message(message, Common::Timer::GetTimeMs() + ms, rgba));
+  s_messages.emplace(type, Message(std::move(message), Common::Timer::GetTimeMs() + ms, rgba));
 }
 
-void AddMessage(const std::string& message, u32 ms, u32 rgba)
+void AddMessage(std::string message, u32 ms, u32 rgba)
 {
   std::lock_guard<std::mutex> lock(s_messages_mutex);
   s_messages.emplace(MessageType::Typeless,
-                     Message(message, Common::Timer::GetTimeMs() + ms, rgba));
+                     Message(std::move(message), Common::Timer::GetTimeMs() + ms, rgba));
 }
 
 void DrawMessages()

Source/Core/VideoCommon/OnScreenDisplay.h

@@ -37,10 +37,11 @@ constexpr u32 VERY_LONG = 10000;
 };  // namespace Duration
 
 // On-screen message display (colored yellow by default)
-void AddMessage(const std::string& message, u32 ms = Duration::SHORT, u32 rgba = Color::YELLOW);
-void AddTypedMessage(MessageType type, const std::string& message, u32 ms = Duration::SHORT,
+void AddMessage(std::string message, u32 ms = Duration::SHORT, u32 rgba = Color::YELLOW);
+void AddTypedMessage(MessageType type, std::string message, u32 ms = Duration::SHORT,
                      u32 rgba = Color::YELLOW);
-void DrawMessages();  // draw the current messages on the screen. Only call once
-                      // per frame.
+
+// Draw the current messages on the screen. Only call once per frame.
+void DrawMessages();
 void ClearMessages();
 }  // namespace OSD

Source/DSPTool/DSPTool.cpp

@@ -22,7 +22,7 @@ u8 DSP::Host::ReadHostMemory(u32 addr)
 void DSP::Host::WriteHostMemory(u8 value, u32 addr)
 {
 }
-void DSP::Host::OSD_AddMessage(const std::string& str, u32 ms)
+void DSP::Host::OSD_AddMessage(std::string str, u32 ms)
 {
 }
 bool DSP::Host::OnThread()