Top level deeplink handling (#1660)

* Handle link opening on the top most levels and prepare for percolating them throughout the app
* Add support for a custom app scheme
* Add specific AppRoute parsers.
* Integrate custom scheme in the AppRouteURLParser
* Switch to `element://call` and cleanup route parsing

ElementX/Sources/Application/Application.swift

@@ -35,7 +35,14 @@ struct Application: App {
         WindowGroup {
             appCoordinator.toPresentable()
                 .statusBarHidden(shouldHideStatusBar)
-                .onOpenURL { appCoordinator.handleUniversalLink($0) }
+                .environment(\.openURL, OpenURLAction { url in
+                    if appCoordinator.handleDeepLink(url) {
+                        return .handled
+                    }
+
+                    return .systemAction
+                })
+                .onOpenURL { appCoordinator.handleDeepLink($0) }
                 .introspect(.window, on: .iOS(.v16)) { window in
                     // Workaround for SwiftUI not consistently applying the tint colour to Alerts/Confirmation Dialogs.
                     window.tintColor = .compound.textActionPrimary