[Feature] Allow a section to be hidable i.e. not everything to left of 'bar' as it is now

[pskowronek]

A feature request: Allow a section to be hidable i.e. not only everything to left, but only part (a section).

Add an option where could be an additional "bar" ("|") so everything between left '|' and right '|' could be hidden.

Use case - having mac 13 or 14" and opened application with wide menu, the menu items disappear on the left side. Another use-case is macbook with notch, when if you have something like Menu Meters and a couple of other menubar apps they quickly disappear under the notch. If there was an option in Hidden Bar to collapse a section, then icons on the left could be now visible and accessible when section collapsed. Very helpful if you have Menu Meters (cpu/mem gauges) and still you have some apps that you would like to be able to use. This potentially could address problems stated in #292, #280.

[sergey-seleznev]

I use Doll to display notification icons in the menu bar (i.e. Slack messages). I prefer to "Hide icon if monitored app isn't running" in its settings. This makes the icons appear in the left-most side when notifications come. However, Hidden Bar effectively hides those :( I love both apps, but they don't play well together this way.