legal cookbook build failed due to Nonetype error while retrieving cases

[rakshit-naidu-gt]

Issue -- The current build does not pass.
Why -- There is a 'Nonetype' error that occurs while retrieving the cases.
Reason -- The implementation tries to retrieve using case_id. However, this case_id does not match up with the table which prompts the 'Nonetype' error (as none of the cases can be pulled up from the DB).
Resolved -- using the source_id so that now both the vector store and the DB can be connected.