Add ability to collapse right hand sidebar in merge request

Release notes

The right hand side bar in the merge request view/window is permanent. This is considered a waste of space by myself and other developers at my company. While it has information that is important to some, it's not something I use very often and I only want to see it when I ask for it, otherwise I see it as a distraction from my primary task as a reviewer or as a review owner -- which is to understand what the current changes are.

I understand that some individuals find value in this information. I'm not asking for it to be removed, I asking for the ability to collapse the RIGHT hand side bar. Also, please don't design a product that works best when expanded to full screen. I believe 1080p is a fairly standard monitor size now, don't assume you get any more than half that width.

The following image illustrates the side bar that I want the ability to collapse.

Problem to solve

Current merge request screen permanently wastes space on the right hand side with it's sidebar. While this information is useful to some, it's not useful to all, nor is it useful to the primary purpose of a merge request. I view the primary purpose of a merge request as to present a modification to be merged into source base and communications on those changes. The right hand side bar information is primarily for merge request management, which I do not view as a primary purpose of a merge request.

Proposal

The proposal is to modify the right hand side bar so that it is collapsible. This has already been done for the left hand side bar. A similar solution for the right hand would be good too as it provides and ability to remove distractions from the work, but allows it to be accessed when needed.

Intended users

The intended users of this would be anyone that creates or performs code review. Upon reviewing the GitLab personas, I feel it would apply to the following:

Feature Usage Metrics

I do not know.