Fix handle_es_request_error returning 400 instead of 500

[varadekd]

• Issue: https://github.com/DOAJ/doajPM/issues/4120

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Fix handle_es_request_error returning 400 instead of 500

elasticsearch.exceptions.RequestError is a server-side fault (malformed query from the app), not a client error. Return 500 with the standard error description to correctly reflect this.

This PR...

• has scripts to run
• has migrations to run
• adds new infrastructure
• changes the CI pipeline
• affects the public site
• affects the editorial area
• affects the publisher area
• affects the monitoring

Developer Checklist

Developers should review and confirm each of these items before requesting review

• Code meets acceptance criteria from issue
• Unit tests are written and all pass
• User Test Scripts (if required) are written and have been run through
• Project's coding standards are met
  • No deprecated methods are used
  • No magic strings/numbers - all strings are in constants or messages files
  • ES queries are wrapped in a Query object rather than inlined in the code
  • Where possible our common library functions have been used (e.g. dates manipulated via dates)
  • Cleaned up commented out code, etc
  • Urls are constructed with url_for not hard-coded
• Code documentation and related non-code documentation has all been updated
  • Core model documentation has been added to if needed: https://docs.google.com/spreadsheets/d/1lun2S9vwGbyfy3WjIjgXBm05D-3wWDZ4bp8xiIYfImM/edit
  • Events and consumers documentation has been added if needed: https://docs.google.com/spreadsheets/d/1oIeG5vg-blm2MZCE-7YhwulUlSz6TOUeY8jAftdP9JE/edit
• Migation has been created and tested
• There is a recent merge from develop

Reviewer Checklist

Reviewers should review and confirm each of these items before approval
If there are multiple reviewers, this section should be duplicated for each reviewer

• Code meets acceptance criteria from issue
• Unit tests are written and all pass
• User Test Scripts (if required) are written and have been run through
• Project's coding standards are met
  • No deprecated methods are used
  • No magic strings/numbers - all strings are in constants or messages files
  • ES queries are wrapped in a Query object rather than inlined in the code
  • Where possible our common library functions have been used (e.g. dates manipulated via dates)
  • Cleaned up commented out code, etc
  • Urls are constructed with url_for not hard-coded
• Code documentation and related non-code documentation has all been updated
  • Core model documentation has been added to if needed: https://docs.google.com/spreadsheets/d/1lun2S9vwGbyfy3WjIjgXBm05D-3wWDZ4bp8xiIYfImM/edit
  • Events and consumers documentation has been added if needed: https://docs.google.com/spreadsheets/d/1oIeG5vg-blm2MZCE-7YhwulUlSz6TOUeY8jAftdP9JE/edit
• Migation has been created and tested
• There is a recent merge from develop

Testing

List user test scripts that need to be run

List any non-unit test scripts that need to be run by reviewers

Deployment

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Configuration changes

What configuration changes are included in this PR, and do we need to set specific values for production

Scripts

What scripts need to be run from the PR (e.g. if this is a report generating feature), and when (once, regularly, etc).

Migrations

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Monitoring

What additional monitoring is required of the application as a result of this feature

New Infrastructure

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Continuous Integration

What CI changes are required for this