title: Total column in matrix table
body: <p>I need to add to matrix report column called "total" that will sum values from number fields as shown on the picture:</p>
  
  <p><img src="https://i.stack.imgur.com/shH61.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/5TZla.png" alt="enter image description here"></p>