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/FrequentlyUsedEmoji.swift

@@ -0,0 +1,15 @@
+//
+// Copyright 2025 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.
+//
+
+struct FrequentlyUsedEmoji: Codable, Hashable {
+    let count: UInt
+    let key: String
+    
+    static func == (lhs: FrequentlyUsedEmoji, rhs: FrequentlyUsedEmoji) -> Bool {
+        lhs.key == rhs.key
+    }
+}