"results per page" search issues

[532910]

1. Open https://metacpan.org/ and search something, like Mason::Plugin for example.
2. Scroll to the end and to go the second page: https://metacpan.org/search?p=2&q=Mason%3A%3APlugin&size=20
3. Scroll to the end and switch to 500 results per page: https://metacpan.org/search?p=2&q=Mason%3A%3APlugin&size=500 -> you'll see no results at all.

[mohawk2]

I think the p parameter should probably be a from parameter. That would decouple what page you're on from how many things to show. That would influence #2223 which is otherwise a good approach.