Implement onDropStart, onDropEnd for file dropping (#1583)

* native side

* Theoretically, things should work

* brurh forgot a letter

* another quick cpp fix

* everything works now

* onDropText isnt fully supported

* Fix typo.

* Remove accidental cSpell addition to settings.json

* Dispatch `onDropStart` and `onDropEnd` events in HTML5.

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Co-authored-by: player-03 <player3.14@gmail.com>

project/include/ui/DropEvent.h

@@ -11,7 +11,10 @@ namespace lime {
 
 	enum DropEventType {
 
-		DROP_FILE
+		DROP_FILE,
+		DROP_TEXT,
+		DROP_BEGIN,
+		DROP_COMPLETE
 
 	};