Utils: Markdown: Use existing icons for code copy buttons

Change-Id: I6b6f6791b6b0acba56bb1e978876a65a1756e391
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/libs/utils/markdownbrowser.cpp

@@ -110,8 +110,8 @@ public:
     }
     static QIcon icon(bool isCopied)
     {
-        static QIcon clickedIcon(":/markdownbrowser/images/checkmark.png");
+        static QIcon clickedIcon = Utils::Icons::OK.icon();
-        static QIcon unclickedIcon(":/markdownbrowser/images/code_copy_square.png");
+        static QIcon unclickedIcon = Utils::Icons::COPY.icon();
         if (isCopied)
             return clickedIcon;
         return unclickedIcon;

src/libs/utils/utils.qrc

@@ -303,10 +303,4 @@
         <file>images/classrelationbackground.png</file>
         <file>images/classrelationbackground@2x.png</file>
     </qresource>
-    <qresource prefix="/markdownbrowser">
-        <file>images/code_copy_square.png</file>
-        <file>images/code_copy_square@2x.png</file>
-        <file>images/checkmark.png</file>
-        <file>images/checkmark@2x.png</file>
-    </qresource>
 </RCC>