DEV-15453: Updated ES sanitizing functions to handle sanitization byp…

[gregrholden]

Description:

DEV-15453: Sanitize OpenSearch Input

• Vulnerability scan finding f022 stated that the es_minimal_sanitize length-comparison logic returns unsanitized input when the removals equal escapes.
• The fix was to ensure the sanitizing function returns the sanitized input regardless of length comparison and then apply that sanitization to the keyword search class.
• Unit tests were added to cover the reported vulnerability parameters/vectors.

Technical Details:

1. In search/v2/es_sanitization.py (lines 38-54): Changed function to always return the processed_string instead of the keyword variable that got assigned the processed_string value only if the lengths were not equal, which eliminates the length-equality bypass vulnerability and ensures the return value is always a sanitized version of the input.
2. In common/query_with_filters.py (lines 197-202): Applied the above sanitization to the _KeywordSearch class before passing values to the ES_Q query string.
3. Added more test cases to search/tests/unit/test_elasticsearch_helpers.py to validate changes made.
4. Fixed missing return types and import ordering to pass lint tests.

Requirements for PR Merge:

1. Unit & integration tests updated
2. API documentation updated (examples listed below)
   1. API Contracts
   2. API UI
   3. Comments
3. Data validation completed (examples listed below)
   1. Does this work well with the current frontend? Or is the frontend aware of a needed change?
   2. Is performance impacted in the changes (e.g., API, pipeline, downloads, etc.)?
   3. Is the expected data returned with the expected format?
4. Appropriate Operations ticket(s) created
5. Jira Ticket(s)
   1. DEV-0

Explain N/A in above checklist:

[james-at-kc]

LGTM. instead of returning original string. now returns sanitized string regardless if len is same or not. Ready for merge.