[OpenSmalltalk/opensmalltalk-vm] eb2ee2: Use NSWindow API for changing fullscreen mode (#478)

 
  Branch: refs/heads/Cog
  Home:   https://github.com/OpenSmalltalk/opensmalltalk-vm
  Commit: eb2ee2c9247dbc4c18249435954b4363db88627e
      https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/eb2ee2c9247dbc4c18249435954b4363db88627e
  Author: Fabio Niephaus <[hidden email]>
  Date:   2020-02-28 (Fri, 28 Feb 2020)

  Changed paths:
    M platforms/iOS/vm/OSX/sqSqueakOSXMetalView.m

  Log Message:
  -----------
  Use NSWindow API for changing fullscreen mode (#478)

* Use NSWindow API for changing fullscreen mode

instead of going through NSView's API. The latter does offer more options, but messes up the fullscreen mode for some reason (UI becomes unresponsive because input events are no longer received).

Using `self.window toggleFullScreen:self` also does not mess with additional displays (only the display showing Squeak is put into fullscreen mode).

* Address reviewer feedback