Fix accent colour not being applied to Alerts etc. (#701)

ElementX/Sources/Application/Application.swift

@@ -22,6 +22,10 @@ struct Application: App {
     private let applicationCoordinator: AppCoordinatorProtocol
 
     init() {
+        // Set the tint colour app-wide. Using UIView ensures that alerts, confirmation dialogs
+        // and Xcode previews all take on the tint colour, similar to defining it in an asset catalog.
+        UIView.appearance().tintColor = .element.accent
+        
         if Tests.isRunningUITests {
             applicationCoordinator = UITestsAppCoordinator()
         } else {
@@ -35,7 +39,6 @@ struct Application: App {
                 EmptyView()
             } else {
                 applicationCoordinator.toPresentable()
-                    .accentColor(.element.accent)
                     .task {
                         applicationCoordinator.start()
                     }