Adds drawHierarchyInKeyWindow parameter (#801)

Author: Jelizondo

Sources/SnapshotTesting/Snapshotting/UIViewController.swift

@@ -11,6 +11,9 @@
     ///
     /// - Parameters:
     ///   - config: A set of device configuration settings.
+    ///   - drawHierarchyInKeyWindow: Utilize the simulator's key window in order to render
+    ///     `UIAppearance` and `UIVisualEffect`s. This option requires a host application for your
+    ///     tests and will _not_ work for framework test targets.
     ///   - precision: The percentage of pixels that must match.
     ///   - perceptualPrecision: The percentage a pixel must match the source pixel to be considered a
     ///     match. 98-99% mimics
@@ -20,6 +23,7 @@
     ///   - traits: A trait collection override.
     public static func image(
       on config: ViewImageConfig,
+      drawHierarchyInKeyWindow: Bool = false,
       precision: Float = 1,
       perceptualPrecision: Float = 1,
       size: CGSize? = nil,
@@ -34,7 +38,7 @@
         snapshotView(
           config: size.map { .init(safeArea: config.safeArea, size: $0, traits: config.traits) }
             ?? config,
-          drawHierarchyInKeyWindow: false,
+          drawHierarchyInKeyWindow: drawHierarchyInKeyWindow,
           traits: traits,
           view: viewController.view,
           viewController: viewController