Allow the sidebar to be hidden or shown

[eric-g-97477]

Is your feature request related to a problem? Please describe.
The side bar which contains the list of the subscriptions takes up a lot of horizontal space. While it can be resized, it is annoying to need to spend the time resizing it back and forth.

Describe the solution you would like
A button with a key equivalent to show or hide the side bar maintaining its width when shown.

Describe alternatives you have considered
None. This is a common feature across many applications.

[Eitot]

The actual implementation seems to be fairly trivial, but I am not sure if this will work without issues. It might be possible to implement this as a hidden feature first.