[tools/CouchDB_Confirm_Integrity] Add case where VL doesn't exist in SQLDB

[zaliqarosli]

Brief summary of changes

• [ ] Have you updated related documentation?

Testing instructions (if applicable)

1. Delete a session in SQL DB that has data associated with it i.e. instrument data
2. On main branch, run php tools/CouchDB_Confirm_Integrity.php. Go to the DQT, run a query with instrument data fields and notice that your deleted session data is still there.
3. On this PR branch, run php tools/CouchDB_Confirm_Integrity.php again. In the script output, you should see a print out that flags the deleted session. Go to the DQT, using the same query as you used above, notice that your deleted session data is no longer there.

Link(s) to related issue(s)

• Resolves # (Reference the issue this fixes, if any.)

[CamilleBeau]

Manual tests went well!