Improve layout for reimbursement list

[raucao]

• It's showing all reimbursements with all line items currently, so the page is rather long. I think we can hide the line items by default for confirmed reimbursements, and only show them upon click/user action.
• Vetoed records appear for too long. It's not useful to see them long after the veto happened, but maybe there could/should be a button to show all vetoed ones if someone wants to see them.

[raucao]

Found a better solution for the second point, which was just applying the solution for point 1: hide line items by default for vetoed reimbursements. Much better than hiding the whole entry, and looks neat and clean now.