Fixes two Django 1.11 to 3.2 upgrade issues in search.

[rtibbles]

Summary

Description of the change(s) you made

• Adds basic coverage for some commonly used filters on search endpoint.
• Fixes extant use of user.is_anonymous as a method not a property
• Updates django_filter initialization arguments from name to field_name

Manual verification steps performed

1. Search for anything on the search page
2. See no 500s

Screenshots (if applicable)

Does this introduce any tech-debt items?

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Reviewer guidance

How can a reviewer test these changes?

Are there any risky areas that deserve extra testing?

References

Fixes #3168

Comments

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Contributor's Checklist

PR process:

• If this is an important user-facing change, PR or related issue the CHANGELOG label been added to this PR. Note: items with this label will be added to the CHANGELOG at a later time
• If this includes an internal dependency change, a link to the diff is provided
• The docs label has been added if this introduces a change that needs to be updated in the user docs?
• If any Python requirements have changed, the updated requirements.txt files also included in this PR
• Opportunities for using Google Analytics here are noted
• Migrations are safe for a large db

Studio-specifc:

• All user-facing strings are translated properly
• The notranslate class been added to elements that shouldn't be translated by Google Chrome's automatic translation feature (e.g. icons, user-generated text)
• All UI components are LTR and RTL compliant
• Views are organized into pages, components, and layouts directories as described in the docs
• Users' storage used is recalculated properly on any changes to main tree files
• If there new ways this uses user data that needs to be factored into our Privacy Policy, it has been noted.

Testing:

• Code is clean and well-commented
• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Any new interactions have been added to the QA Sheet
• Critical and brittle code paths are covered by unit tests

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Reviewer's Checklist

This section is for reviewers to fill out.

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[bjester]

Quick scan of the code looks good

[pcenov]

@rtibbles I'm not getting the 500 error anymore but cannot say that the search is working now as I'm constantly getting 524 timeout errors regardless of the entered search term.

I thought that these timeouts might be temporary but it's been happening for the past several hours. Should I file a separate issue for that?

[radinamatic]

Confirmed, 504 and 524 errors keep search from working properly.

Firefox	Chrome