Extract reload logic into wrapper component and use for new homepage

What does this MR do and why?

Extract reload logic from our Todos Dashboard into a reusable component, and use it for widgets on the new (not yet released) homepage.

References

Part of Automatically refresh content when returning to... (#552077 - closed).

Also related to #552653 (closed) and other widgets of our new homepage (&16657 (closed)).

Screenshots or screen recordings

recording_1751464354

How to set up and validate locally

• Enable the personal_homepage feature flag and set "Personal homepage" as your homepage preference at http://gdk.test:3000/-/profile/preferences
• Vist the root URL / and see the widgets showing a loading indicator while fetching data.
• Let them finish, switch to a different tab, and switch back.
• See the widgets refetch their data, showing loading indicators again.
• Resolve a todo on the homepage and confirm there is no loading spinner while updating todos. (That would be super distracting.)

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.