Changes

Amazon invoices: report the PDF as available when it sits on the iDempiere document

Rows migrated from the local file (and rows rebuilt from documents) carry no file
of their own — their original PDF is the document's attachment. The list flagged
them as "no PDF" although the link works; they now show "Anhang".

Amazon invoices: confirm every import with the cost type shown, no remembered cost types

12 fee invoices were booked to "Werbekosten": the page remembered the last
selection of each cost-type box in the browser and a stale value silently
overrode the correct default.

- cost types are no longer stored in the browser (old keys are removed); every
  page load starts from the server defaults (Ads → Werbekosten, fees/credit notes
  → Amazon Gebühren); a deviation is flagged (amber summary, reset to default)
- every import goes through a confirmation dialog that groups the invoices by
  type, shows the cost type each group will be booked to (changeable there, the
  default is marked, a deviation is highlighted) and lists already booked ones as
  skipped. It opens on "Ausgewählte importieren" and right after an upload
  ("jetzt importieren" / "Später")
- the import result names the cost type that was used per invoice