Track amount and settled amount on transaction statuses

Previously this required looking up in the notification, but it makes sense
to materialize this in the transaction status, to make it easier to work
with.

We also now track the settled amount separately, so we can summarize the fees
easily.
Include download information about reports

Include both when the report is downloaded as well as the full contents
of the downloaded report in the database.
Include settled date and amount in admin list
Ensure pspreference is unique, and show it in the logs
Track which payment method is being used
Add tool to process reports from Adyen

Process accounting reports to update our own transaction status, as well
as summarizing the settlement batch reports in email to treasurer.
Invert log to show red=error

"error=true" caused green - so change the admin view to instead show
"success=false" in those cases, making green=good and red=bad again.
Add tool to send Adyen error reports