refactor Search

- have a separate body view for each os
- macOS: set navigation title for search
- macOS: set min width to 835 for main content
- macOS: set main window min height to 600
- macOS: don’t have text behind the cancel button
- split SearchTextField into macOS and iOS/tvOS
- iOS: move search menu to the right
- iOS: unified search field
- make min width a constant
- add option to disable search suggestions

Signed-off-by: Toni Förster <toni.foerster@gmail.com>

Shared/Assets.xcassets/SearchTextFieldBackground.colorset/Contents.json

@@ -0,0 +1,38 @@
+{
+  "colors" : [
+    {
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "1.000",
+          "green" : "1.000",
+          "red" : "1.000"
+        }
+      },
+      "idiom" : "universal"
+    },
+    {
+      "appearances" : [
+        {
+          "appearance" : "luminosity",
+          "value" : "dark"
+        }
+      ],
+      "color" : {
+        "color-space" : "srgb",
+        "components" : {
+          "alpha" : "1.000",
+          "blue" : "0.110",
+          "green" : "0.110",
+          "red" : "0.118"
+        }
+      },
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}