TextEditor: Add sortSelectedLines action

Change-Id: Ifdc82766bac3cfe2e9c287b4ef04902a943c8f72
Reviewed-by: André Hartmann <aha_1980@gmx.de>

src/plugins/texteditor/texteditor.h

@@ -423,6 +423,8 @@ public:
     void uppercaseSelection();
     void lowercaseSelection();
 
+    void sortSelectedLines();
+
     void cleanWhitespace();
 
     void indent();