"Open all selected" does not work on folders

Is your feature request related to a problem? Please describe.
I'm not sure if this is considered a bug or a feature request (possibly both), but at the moment, clicking on "Open all selected" when a single folder is selected does not open any bookmarks. I would expect that all bookmarks inside the folder be opened when I do click on it.

Describe the solution you'd like
It would also be nice for the sake of convenience to add an "Open all bookmarks" menu entry to folders, which is common in most web browsers. When I open a new browser window, it can be a bit of a hassle to click on or select each bookmark one at a time until all of them are opened (individually or with "Open all selected"). This happens a lot for the many pages that I open regularly (e.g. for work).

Describe alternatives you've considered
I don't see a "Select all bookmarks" button either; that can be another option to make "Open all selected" more viable to use, although this would still require an extra click navigating inside the folder first if selecting the folder is not an option, making it slightly more inconvenient.

Start by locating the implementation of "Open all selected" and the folder menu in the JavaScript frontend, then reproduce the behavior with a folder containing bookmarks. Confirm the desired result by opening all bookmarks in a selected folder, and check whether the folder menu also provides an "Open all bookmarks" action or whether selecting all bookmarks is the intended alternative.