Modify menu item for Picogreen Quantification

Picogreen quantification is used for both the 16S and shotgun workflows, and is listed under 'General Workflow'. It will not be part of the MiniPCR workflow however. Hence we should decide whether this item gets migrated to under both 16S and Shotgun workflows, or whether it's understood that not all General Workflow items need to be used in a workflow.