Function to get expected barcode from statusDB

This program is being used during demultiplexing to extract barcodes from the fastq files.
Added a function for getting the expected barcode from statusDB. Useful when it is not present in the csv samplesheet.
@Galithil I think this should work during the demultiplexing. I could not go back enough revisions for the some relevant projects in statusDB to confirm this though.