Don't cherry-pick:

Don't cherry-pick:
- introduced administrative action backing bean for receipt items
- introduced converter for receipt items
- introduced uniqueAddReceiptItem() and CDI observers for updating cache/lists
- introduced findReceiptItemById()
- let's distinguish between administrative and user events
- updateReceipt returns now a redirection outcome (back to admin-list-receipts
  view)
- reformatted Java code a bit for having all parameter of huge constructors
  in a separate line
- added missing navigation rules from edit -> list views
- added missing i18n strings

Signed-off-by: Roland Häder <roland@mxchange.org>