Implement platform-agnostic paste in SDL2 backend

extras/videoDrivers/SDL2/VideoSDL2.cpp

@@ -213,29 +213,27 @@ void VideoSDL2::PrintError(const std::string& msg) const
 
 void VideoSDL2::HandlePaste()
 {
-#ifdef _WIN32
-    if(!IsClipboardFormatAvailable(CF_UNICODETEXT))
+    if(!SDL_HasClipboardText())
         return;
 
-    OpenClipboard(nullptr);
-
-    HANDLE hData = GetClipboardData(CF_UNICODETEXT);
-    const wchar_t* pData = (const wchar_t*)GlobalLock(hData);
+    auto* text = SDL_GetClipboardText();
+    if(!text)
+        return;
+    if(text[0] == '\0')
+        PrintError(SDL_GetError());
 
     KeyEvent ke = {KeyType::Invalid, 0, false, false, false};
-    while(pData && *pData)
+    auto* p = text;
+    while(*p)
     {
-        ke.c = *(pData++);
+        ke.c = static_cast<unsigned char>(*(p++));
         if(ke.c == L' ')
             ke.kt = KeyType::Space;
         else
             ke.kt = KeyType::Char;
         CallBack->Msg_KeyDown(ke);
     }
-
-    GlobalUnlock(hData);
-    CloseClipboard();
-#endif
+    SDL_free(text);
 }
 
 void VideoSDL2::DestroyScreen()