TODO: Improve the diff page

[kit-ty-kate]

Reading the last diff is tedious. There are duplicated info, the important changes aren't very well highlighted, …

My current plan is to transform this page into a table similar to the main page:

where:

• the cells that aren't updated will appear empty and white (or another colour to avoid clashes with internal failures)
• each rows will appear from important change to least important change (the same order as today)
• each cell that changes will appear with a gradient from before (left) to now (right). background-image: linear-gradient(to right, #64e178 35%, #ff2800 50%);
• every column available for the two runs will appear (even if they have no diff in them) to keep it consistent

Note: the main /diff page should also be improve by having a table with two column and radio buttons to choose the two run you wanna see a diff of.