Add a feature flag for spaces. (#4429)

* Remove the huge conditional compilation block on AppSettings.

It is still required for the ElementCallBaseURL however.

* Add a feature flag for spaces.

ElementX/Sources/Application/Settings/AnalyticsConfiguration.swift

@@ -0,0 +1,16 @@
+//
+// Copyright 2022-2024 New Vector Ltd.
+//
+// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+// Please see LICENSE files in the repository root for full details.
+//
+
+import Foundation
+
+/// A type that represents how to set up the analytics module in the app.
+struct AnalyticsConfiguration {
+    /// The host to use for PostHog analytics.
+    let host: String
+    /// The public key for submitting analytics.
+    let apiKey: String
+}