[WIP] Add keyboard shortcut s to toggle sidebar visibility

[tfl]

This PR adds a keyboard shortcut s to toggle sidebar visibility

[clefebvre]

Careful here, many hide(), show() calls are called on the sidebar already, when navigating through groups (for series, VOD etc..) and when toggling fullscreen.

Also, if you add shortcuts you need to add the info in the keyboard shortcuts page.

[tfl]

I have tried s in all situations I came across (and made sense to me) and never went into any problem(s) - besides, there was a toggle-sidebar shortcut before!

But you are right: it has to be documented! Will try again ;)

[tfl]

Well, now there is an info bar above the stream. It shows the name of the station and the stream url. Why?
Please! If somebody needs to know the stream URL or the name of the station currently streaming then the information should be available via F1.

[lakshminarayananb]

@tfl this is a neat feature, I earlier submitted a PR to resize the sidebar, this is simpler and neat. Sad that it is not merged.

I took your code and added in my own logic to it to remove the mpv_top_box as well in the version I personally use. This hides the channel and stream url.