This converts the `<AdminPageHeader />` component and the
`<AdminPageSubheader />` components into new components
that can be used outside of admin, and updates the CSS classes.
Also introduces a `<DPageActionButton />` component and child
components for the header action buttons.
I have to keep the old admin-only components around for
now until plugins are updated, then we can remove it,
and remove the re-exports that are done within
admin-page-action-button.gjs
Sometimes changes to "What's new?" feed items are made or the feed items are
removed altogether, and the polling interval to check for new features is 1 day.
This is quite long, so this commit introduces a "Check for updates"
button for admins to click on the "What's new?" page which will bust
the cache for the feed and check again at the new features endpoint.
This is limited to 5 times per minute to avoid rapid sending of
requests.
Currently, a new sidebar link for what's new and reports is going to the main dashboard page and activates the proper tab.
It might be problematic, especially, when the instance has a lot of problems. In that case, it would be difficult for admin to find reports or what’s new which is rendered at the bottom of the page.
Therefore separate pages for reports and what's new were created.
Reports were moved to a component that is shared between a separate page and the dashboard.
