Make the "pager" usable when browsing search results

Shared by a shy user through a private email:

> BTW, I just ran into the pager on Vulnerable Code, this could be improved:
>
> https://public.vulnerablecode.io/packages/search?page=2&search=sudo
>
> If you want to go to page 45 of results, you have to visit each and every single page before it by pressing next 44 times...

We should have better widgets for next/previous pagination... and also:

- [ ] #1618

This is related to:
- https://github.com/aboutcode-org/vulnerablecode/issues/1616