[Qt] fix Qt slot problem in receivecoinsdialog

- fixes error from debug.log:
  QMetaObject::connectSlotsByName: No matching signal for
  on_recentRequestsView_selectionChanged(QItemSelection,QItemSelection)
- small style fixes (e.g. alphabetical ordering if includes etc.)
- fixes #3992
Merge pull request #4136

01ce711 [Qt] fix Qt slot problem in receivecoinsdialog (Philip Kaufmann)