Improve how alias settings are handled, add unit tests (#3686)

ElementX/Sources/Services/Room/RoomInfoProxy.swift

@@ -67,6 +67,37 @@ struct RoomInfoProxy: BaseRoomInfoProxyProtocol {
     var pinnedEventIDs: Set<String> { Set(roomInfo.pinnedEventIds) }
     var joinRule: JoinRule? { roomInfo.joinRule }
     var historyVisibility: RoomHistoryVisibility { roomInfo.historyVisibility }
+    
+    /// Find the first alias that matches the given homeserver
+    /// - Parameters:
+    ///   - serverName: the homserver in question
+    ///   - useFallback: whether to return any alias if none match
+    func firstAliasMatching(serverName: String?, useFallback: Bool) -> String? {
+        guard let serverName else { return nil }
+        
+        // Check if the canonical alias matches the homeserver
+        if let canonicalAlias = roomInfo.canonicalAlias,
+           canonicalAlias.range(of: serverName) != nil {
+            return canonicalAlias
+        }
+        
+        // Otherwise check the alternative aliases and return the first one that matches
+        if let matchingAlternativeAlias = roomInfo.alternativeAliases.filter({ $0.range(of: serverName) != nil }).first {
+            return matchingAlternativeAlias
+        }
+        
+        guard useFallback else {
+            return nil
+        }
+        
+        // Or just return the canonical alias if any
+        if let canonicalAlias = roomInfo.canonicalAlias {
+            return canonicalAlias
+        }
+        
+        // And finally return whatever the first alternative alias is
+        return roomInfo.alternativeAliases.first
+    }
 }
 
 struct RoomPreviewInfoProxy: BaseRoomInfoProxyProtocol {