Add filtering and prioritization of excerpts in API

[samshara]

Caching Mechanism for Operational Learning Summary Generation Endpoint

1. Upon receiving a request to the API, check if the hashed filters are present in the cache.
2. If the hashed filters exist in the cache, return the cached response.
3. If the hashed filters do not exist in the cache, proceed with processing the request.

Important

The keyword search should only work in English. This is to ensure that the caching of excerpts functions properly. If we search for other languages, the cache will become too large, defeating the purpose of having a cache.