Display "à la v24"

[brunob]

I've read that some people miss the v24 display mode which doesn't use panes cf #3002

In #2908 (reply in thread) @wofferl provide clues in order to get something similar, but we can't remove the list pane as he explain in #2964 (comment)

I've also read that the old mode with its infinite scroll was problematic to maintain cf #2994 (comment)

For me the infinite scroll is not needed (doomscrolling spotted), we can navigate from one feed item to antoher with keyboard shortcuts.

So, the only things that miss to get something a bit similar to v24 mode is the ability to hide the list pane aka splitpanes__pane splitpanes__pane-list (i've tested to hide it with a simple display none and it works well). Plus the ability to show the last unread item of the feed after having clicked on a feed in the feed list pane (in order to avoid users to have to use j key every time the switch feeds).

Do you think this can be done ?