[DEV][TASK 10006] Group VBL by partner
[DEV][TASK 10006] Raise error if not the same partner or currency on vbl
[DEV][TASK 10006] Set invoice date to today when merging invoices
[FIX] Remove 'zefzrgf'
[FIX] Raise error when trying to group invoices other than VBL
[MERGE][TASK 10006] Group vessel bilings by partner