Allow side-by-side difference views to be resized

Problem to solve

As a code reviewer, I would like the side-by-side difference viewer to allow for the centre point of the diff table to be 'moved', allowing me to make the "before" or the "after" window wider, similarly to the Web IDE.
We have had multiple instances where the 'before' or the 'after' change is consdierably larger than it's comparison, and having the view split 50/50 isn't the optimal usage of page-space.

Intended users

• Sasha (Software Developer)
• Simone (Software Engineer in Test)

User experience goal

The code reviewer should be able to resize a side by side difference table in the same way as navigating the WebIDE.

Proposal

Allow a user to 'grab' and 'drag' the horizontal centre point of a diff table to resize one side of the diff to be larger than the other.