Sidebar filters shouldn't fully reload the page

[lydiascarf]

I'm pulling this out from #21. It's a usability issue to end up at the top of the page every time the user selects a filter if they then have to scroll back down to where they were.

The most vanilla way to address this would be to add event listeners and modify the DOM manually.

There are also lightweight tools for adding reactivity to sites like alpine.js or datastar. This might be less chaotic than implementing reactivity ourselves, and it could be useful down the line to have access to lightweight reactive UI.

[matamadio]

Moreover on page behaviour topic:

1. Index page is too long - set a max of 30 elements per page
2. Filters order:
   • Categories (rename as "Risk component")
   • Hazard type
   • Geo Scale
   • Countries
   • Projects
   • Catalogue
   • Licenses