Audio Timeline Item support (#612)

* audio timeline item support

* improved the code to reduce cognitive complexity

* no need anymore for this swiftlint disabling of a rule

* pr comments

ElementX/Sources/Services/Timeline/TimelineItems/EventBasedTimelineItemProtocol.swift

@@ -33,7 +33,7 @@ enum TimelineItemGroupState: Hashable {
     }
 }
 
-protocol EventBasedTimelineItemProtocol: RoomTimelineItemProtocol {
+protocol EventBasedTimelineItemProtocol: RoomTimelineItemProtocol, CustomStringConvertible {
     var body: String { get }
     var timestamp: String { get }
     var shouldShowSenderDetails: Bool { get }
@@ -71,4 +71,8 @@ extension EventBasedTimelineItemProtocol {
             }
         }
     }
+
+    var description: String {
+        "\(String(describing: Self.self)): id: \(id), timestamp: \(timestamp), isOutgoing: \(isOutgoing), properties: \(properties)"
+    }
 }