Add QSL final report export

[fdamken]

The QSL final report export is not required to create a pretty PDF file, but to include the following data:

• budget available
• budget spent for books
• percantage of budget spent
• count of ordered books
• count of bought books
• count of students that ordered books
• subvention rate (should be 100%)

This could be realised by adding a field cost to an order and expanding the state field for the state bought.

[Xiphoseer]

The problem with this is that we have no way of knowing the actual price of a single order automatically. While this is very unfortunate, I suspect it is easier to accumulate the budget spent from the receipts received from the bookstore.

[fdamken]

It would be no problem for me to enter the prices manually for each order. Am 21. Juni 2018 08:56:01 MESZ schrieb Xiphoseer <notifications@github.com>:

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The problem with this is that we have no way of knowing the actual price of a single order automatically. While this is very unfortunate, I suspect it is easier to accumulate the budget spent from the receipts received from the bookstore. -- You are receiving this because you authored the thread. Reply to this email directly or view it on GitHub: #64 (comment)

[Xiphoseer]

You can already set the price for a book. Would you prefer to have that price moved to the order instead, as it may change from time to time?

[akwick]

I think that having a price for an order is more useful at least for a first version. Besides concurrency changes, entering an amount for an order is less work than adding prices for (hopefully) several books.