I want to remember the opening and closing of the accordion of groups

[takoring]

Is your feature request related to a problem? Please describe.
Dashboard display slows down when registering multiple groups and endpoints

Describe the solution you'd like
I want to remember the open / closed state of the group accordion
Those with an accordion closed do not access /oas (access /oas when the accordion is open)

[nonoakij]

#790
The group accordion open / closed state is now saved in local storage.
(However, all endpoints have still been fetched.)