Describe the bug

Currently, the synonyms are case-sensitive. It will not give the right result if the words do not exactly match.

Steps to Reproduce

1. Create a synonym alternative set for “hoodie” and "sweatshirt.”
2. Search for the Hoodie on the frontend. 

Screenshots, screen recording, code snippet

No response

Environment information

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WordPress and ElasticPress information

No response

Code of Conduct

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