GODT-1113: Fix tray icon size on macOS Big Sur.

Add patched libqcocoa based on Qt 5.13.0

Makefile

@@ -165,6 +165,7 @@ THERECIPE_ENV:=github.com/therecipe/env_${TARGET_OS}_amd64_513
 # therecipe/env in order to download it only once
 vendor-cache/${THERECIPE_ENV}:
 	git clone https://${THERECIPE_ENV}.git vendor-cache/${THERECIPE_ENV}
+	if [ "${TARGET_OS}" == "darwin" ]; then cp -f "./utils/QTBUG-88600/libqcocoa.dylib" "./vendor-cache/${THERECIPE_ENV}/5.13.0/clang_64/plugins/platforms/"; fi;
 
 # The command used to make symlinks is different on windows.
 # So if the GOOS is windows and we aren't crossbuilding (in which case the host os would still be *nix)

utils/QTBUG-88600/README.txt

@@ -0,0 +1,3 @@
+This is version of libqcocoa obtained from original Qt 5.13.0 source available at https://github.com/qt/qtbase with patch from cocoa.patch applyed. 
+
+Please refer to https://bugreports.qt.io/browse/QTBUG-88600 for patch origin and https://doc.qt.io/qt-5/macos-building.html for instructions how to build Qt from source.

utils/QTBUG-88600/cocoa.patch

@@ -0,0 +1,12 @@
+diff --git a/src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm b/src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm
+index 4982f5ee05..3ae1e4fca3 100644
+--- a/src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm
++++ b/src/plugins/platforms/cocoa/qcocoasystemtrayicon.mm
+@@ -224,6 +224,7 @@ void QCocoaSystemTrayIcon::updateIcon(const QIcon &icon)
+         r.moveCenter(fullHeightPixmap.rect().center());
+         p.drawPixmap(r, pixmap);
+     }
++    fullHeightPixmap.setDevicePixelRatio(devicePixelRatio);
+ 
+     NSImage *nsimage = static_cast<NSImage *>(qt_mac_create_nsimage(fullHeightPixmap));
+     [nsimage setTemplate:icon.isMask()];