Replace the ServiceLocator with direct dependency injection (#5548)

Removes the ServiceLocator singleton and instead directly injects the dependencies it was holding for more control over instantiation of the various component subtrees and better visibility over how they're being used.

UnitTests/Sources/ServerConfirmationScreenViewModelTests.swift

@@ -16,18 +16,17 @@ final class ServerConfirmationScreenViewModelTests {
     var clientFactory: AuthenticationClientFactoryMock!
     var client: ClientSDKMock!
     var service: AuthenticationServiceProtocol!
-    var appSettings: AppSettings!
-    
+
     var viewModel: ServerConfirmationScreenViewModel!
     var context: ServerConfirmationScreenViewModel.Context {
         viewModel.context
     }
-    
+
+    private let appSettings: AppSettings
+
     init() {
         AppSettings.resetAllSettings()
         appSettings = AppSettings()
-        // These app settings are kept local to the tests on purpose as if they are registered in the
-        // ServiceLocator, the providers override that we apply will break other tests in the suite.
     }
     
     deinit {
@@ -367,7 +366,7 @@ final class ServerConfirmationScreenViewModelTests {
         viewModel = ServerConfirmationScreenViewModel(authenticationService: service,
                                                       mode: mode,
                                                       authenticationFlow: authenticationFlow,
-                                                      appSettings: ServiceLocator.shared.settings,
+                                                      appSettings: appSettings,
                                                       userIndicatorController: UserIndicatorControllerMock())
         
         // Add a fake window in order for the OAuth flow to continue