DisplayServerWindows handles event multiple times

[ThakeeNathees]

Godot version: 307b1b3

OS/device including version: Windows10

Issue description:
WindowsDisplayServer seems to handle the same event twice(sometimes more) when focus changes to another window.

1. copy a text and paste in gdscript editor with ctrl+v( works fine ) and right click menu click paste (pasting twice)
2. in AnimatedSprite2D add a texture from a file, select with double click -> adds the frame twice
3. in the scene tree rightclick menue click Expand/Collapse All nothings happen because it expand and collapse at the same time
4. in gdscript editor right click on an opened script file and click close -> it close 2 files at the same time
5. Permanent black rectangle #37322
6. Creating a node by double-click will create two copies #37331
7. Editor crash when creating Window node #37329
8. etc.,

A similar fix like #37339 need for windows display server.