One menu opening should close the others

Looking into this.

Maybe put this logic on sidebar level?

I personally not really like this:

            if (prevOpened && prevOpened !== button) {
              Drupal.behaviors.navigationProcessToolbarMenuTriggers.toggleButtonState(prevOpened, false);
            }

We have this logic for popovers with CustomEvents:
https://git.drupalcode.org/project/navigation/-/blob/1.x/js/sidebar.js?r...

I know that we search buttons twice. But this is payment for simple structure.

I would add my remark regarding javascript in module - we have many javascript files with too splitted logic from my point of view. For example expanding/collapsing behavior - we have different classnames and data attributes for 1st level buttons and 2nd level buttons. But actually the main goal of these buttons is just to expand/collapse, so these elements should be unified in this term and expanding behavior should be written in one drupal behavior (which controls all these buttons no matter on which levels they are).

I let @finnsky or other guys to complete this issue

Re #8
In fact second level button is just expand/collapse first level one is much complicated in terms of hover popover and tooltips. that why i splitted this js.

Added imo simpler version. Please review!

#7 not fixed.

When you expanding new menu, all child els should be collapsed by default unless it's an active element (but not sure if we have to check if element is active or not). I'm thinking that by default element is already active and all its tree is expanded. Means if user decided to collapse parent menu -> child should be collapsed aswell no matter if it's active element or not.

It is concurred with #12 that in instances where the parent menu undergoes a collapse, the associated child menu items should likewise undergo a collapse, specifically if they are not currently in an active state.

So!

In my point of view Component (Popover, Menu, Tooltip) only should control own state.
And all common logic will stay on sidebar.js level.
All communication between Navigation Components happens in one place via Custom Events bubbles.

Please review!

Looks good to me. Working as expected for Parent menus. I am assuming we will not collapse child menus when other one is expanded for example under "Configuration" menu.

The fastest option was to create new MR instead of doing hard rebases.
MR 151 opened, and i moved manually all the changes from the previous MR 141. Previous MR worked perfectly and i wanted to merge it and change status to "Fixed", but since hard rebase / recreation of the new MR -> this issue needs review again

I examined it in the live preview, and it functioned correctly.