chore: Generalized Search - implement simple query, refactor queries [CHI-3004]

[GPaoloni]

Description

This PR

• Introduces simple queries.
• Refactors search over content (case, case section, contact, transcript) to use the above. This approach is more resilient to direct user input while also simplifies the code used to generate queries, at the expense of loosing some custom weights we introduced when originally implemented.

The reason for this change is to prevent bugs being thrown by our ElasticSearch services when users introduced special characters. Another option (for historical purposes) was to escape the special characters, but that feels like a more fragile approach. See #759.

Checklist

• Corresponding issue has been opened
• New tests added
• Feature flags / configuration added

Verification steps

• Deploy to development.
• Confirm search works as expected.
  • For advanced queries check the documentation on simple queries linked above.
• Confirm special characters do not break the service.

AFTER YOU MERGE

1. Cut a release tag using the GitHub workflow. Wait for it to complete and notify in the #aselo-deploys Slack channel.
2. Comment on the ticket with the release tag version AND any additional instructions required to configure an environment to test the changes.
3. Only then move the ticket into the QA column in JIRA

You are responsible for ensuring the above steps are completed. If you move a ticket into QA without advising what version to test, the QA team will assume the latest tag has the changes. If it does not, the following confusion is on you! :-P

[stephenhand]

LGTM - was I mistaken to think we could 'globally fuzz' the query? 🙈