Revert "use isDm from the SDK to determine if a room is a direct one to one room."

This reverts commit 58d0841bedb9cc40bd5880a76f3cc1f56c3b8bdb.

ElementX/Sources/Services/Room/RoomInfoProxyProtocol.swift

@@ -38,7 +38,6 @@ protocol RoomInfoProxyProtocol: BaseRoomInfoProxyProtocol {
     var isDirect: Bool { get }
     var isSpace: Bool { get }
     var isFavourite: Bool { get }
-    var isDM: Bool { get }
     
     var canonicalAlias: String? { get }
     var alternativeAliases: [String] { get }