Trim whitespace from beginning and end of the barcode in checkout.

Signed-off-by: Pasi Kallinen <pasi.kallinen@pttk.fi>
Signed-off-by: Ben Shum <bshum@biblio.org>
Add release note for checkout trimming whitespaces from beginning and end of barcodes

Signed-off-by: Ben Shum <bshum@biblio.org>