Add the back-to-top arrow in the home page as it is in the events page

**Is your feature request related to a problem? Please describe.**
We have a back-to-top arrow button in the events page which helps to go on top of the page instantantly. We do not have the feature in the home page as of now

**Describe the solution you'd like**
It would be good to add this feature in the home page as well.

Compare the existing back-to-top arrow on the events page with the home page implementation. Start by locating the two page entry points and the events page's button behavior, then add the equivalent home-page behavior and verify that the arrow appears and returns the page to the top.

Scritto dal modello di indicizzazione a partire dal testo della issue.