Send the Signup analytics event (#6118)

* Implement the Signup event from AuthenticationViewController.

Use AuthenticationFlow instead of MXKAuthenticationType.
Create new AuthenticationType that aligns with AnalyticsEvent naming.
Add additional cases from AnalyticsEvents.

RiotSwiftUI/Modules/Authentication/Common/Service/MatrixSDK/AuthenticationService.swift

@@ -98,7 +98,7 @@ class AuthenticationService: NSObject {
         let loginWizard = LoginWizard()
         self.loginWizard = loginWizard
         
-        if flow == .registration {
+        if flow == .register {
             do {
                 let registrationWizard = RegistrationWizard(client: client)
                 state.homeserver.registrationFlow = try await registrationWizard.registrationFlow()
@@ -124,7 +124,7 @@ class AuthenticationService: NSObject {
         switch flow {
         case .login:
             return client.loginFallbackURL
-        case .registration:
+        case .register:
             return client.registerFallbackURL
         }
     }