Prevent unnecessary refreshes and add sort order

[abeglova]

What are the relevant tickets?

closes https://github.com/mitodl/hq/issues/5454

Description (What does it do?)

This pr fixes two related bugs:

1. The search page refreshes if you go to a different tab or just leave the page open for too long
2. If there is no search term, the search results don't have a determined order after the featured resources on the first few pages so that if you refresh https://rc.learn.mit.edu/search/?page=10 a few times, for example the results change. The results are the same from each node but not the same between nodes so if the query is picked up by a different node, the results change. This means that if a user is paging through resources there will be some duplicates and some resources that aren't shown.

For a user this combination of bugs is annoying because if the user clicks through to a learning resource then comes back, they lose their search results

How can this be tested?

• Verify that both the home page and the search page still load everything

• To test 1) Go to http://open.odl.local:8062/search/?page=10. Go to a different tab and stay there for a minute. Come back to your original tab. The page should not refresh

• Unfortunately 2) can't be tested locally, since locally there is only one opensearch node locally. It can be tested on rc

[ChristopherChudzicki]

👍 Looks good to me.