refactor(Core/Misc): enforce east-const style and add codestyle check (#26492)

Co-authored-by: Ludwig <sudlud@users.noreply.github.com>

src/server/shared/Packets/ByteBuffer.h

@@ -469,7 +469,7 @@ public:
         return append((uint8 const*)src, cnt);
     }
 
-    template<class T> void append(const T* src, std::size_t cnt)
+    template<class T> void append(T const* src, std::size_t cnt)
     {
         return append((uint8 const*)src, cnt * sizeof(T));
     }