🔨 refactor(loading.py): extract persist parameter from params for Chroma vector store instantiation

✨ feat(loading.py): add persist parameter to Chroma vector store instantiation to enable persistence of vector store
The persist parameter is now extracted from the params dictionary before instantiating the Chroma vector store. This improves readability and reduces the complexity of the code. The persist parameter is now added to the Chroma vector store instantiation to enable persistence of the vector store. This allows the vector store to be reused across multiple sessions, improving performance and reducing the time required to load the vector store.