Quantities can now be edited in spreadsheet
Update 'getChemList' query to only list chemicals that are currently in use

-In case of deleted inventory records, we still keep chemicals and
manufacturers even if they're not currently used. Before this update,
all chemicals under a certain CAS number would show up, rather than only
the ones currently in inventory.
Bugfix: Quantity slider is only added once

-Quantity updates when different chemicals are selected for autofill
(scanner)