Usi - 2 behat scenarios added, fixes for incorrect message on user cancellation and number of fixes according to GitHub code-quality

[semteacher]

Fix for incorrect message on user cancellation when consumption is 1 (item fully consumed) Added scenario: Cashier buys three items and cancel purchase when consumption enabled Added scenario: User buys three items and cancel purchase when consumption and discount rounding enabled and cancellation fee given Number of fixes according to GitHub code-quality report