Add support for physical button for page crop (#6091)

See: #2003
In page crop:
physical press button = OK
physical back button = Cancel

frontend/ui/widget/bboxwidget.lua

@@ -49,6 +49,10 @@ function BBoxWidget:init()
             }
         }
     end
+    if Device:hasKeys() then
+        self.key_events.Close = { {"Back"}, doc = "close windows" }
+        self.key_events.Select = { {"Press"}, doc = "confirm adjust" }
+    end
 end
 
 function BBoxWidget:getSize()
@@ -222,4 +226,13 @@ function BBoxWidget:onConfirmAdjust(arg, ges)
     return true
 end
 
+function BBoxWidget:onClose()
+    self.ui:handleEvent(Event:new("CancelPageCrop"))
+end
+
+function BBoxWidget:onSelect()
+    self.ui:handleEvent(Event:new("ConfirmPageCrop"))
+end
+
+
 return BBoxWidget