macOS: Add app icon

Signed-off-by: Roopesh Chander <roop@roopc.net>

WireGuard/WireGuard/UI/macOS/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -1,53 +1,63 @@
 {
   "images" : [
     {
-      "idiom" : "mac",
       "size" : "16x16",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon16.png",
       "scale" : "1x"
     },
     {
-      "idiom" : "mac",
       "size" : "16x16",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon32.png",
       "scale" : "2x"
     },
     {
-      "idiom" : "mac",
       "size" : "32x32",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon32-1.png",
       "scale" : "1x"
     },
     {
-      "idiom" : "mac",
       "size" : "32x32",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon64.png",
       "scale" : "2x"
     },
     {
-      "idiom" : "mac",
       "size" : "128x128",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon128.png",
       "scale" : "1x"
     },
     {
-      "idiom" : "mac",
       "size" : "128x128",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon256.png",
       "scale" : "2x"
     },
     {
-      "idiom" : "mac",
       "size" : "256x256",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon256-1.png",
       "scale" : "1x"
     },
     {
-      "idiom" : "mac",
       "size" : "256x256",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon512.png",
       "scale" : "2x"
     },
     {
-      "idiom" : "mac",
       "size" : "512x512",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon512-1.png",
       "scale" : "1x"
     },
     {
-      "idiom" : "mac",
       "size" : "512x512",
+      "idiom" : "mac",
+      "filename" : "WireGuardMacAppIcon.png",
       "scale" : "2x"
     }
   ],