Address review feedback on the send-failure dialog

- Resolve the send handle at tap time and pass it through the alert,
  removing the duplicated lookup and the stale-itemID window between
  tapping the indicator and pressing Retry.
- Route 'Remove message' through the existing timeline item menu redact
  action instead of a bespoke redact path with a fatalError.
- Surface a retry failure to the user with an indicator toast rather
  than only logging it.
- Only set the send-info accessibility identifier when the label has a
  tappable status, so plain timestamps don't create ambiguous matches.

ElementX/Sources/Screens/Timeline/TimelineModels.swift

@@ -222,7 +222,7 @@ struct ReadReceiptSummaryInfo: Identifiable {
 enum TimelineAlertInfoType: Hashable {
     case audioRecodingPermissionError
     case pollEndConfirmation(String)
-    case sendingFailed(reason: String?, itemID: TimelineItemIdentifier)
+    case sendingFailed(reason: String?, sendHandle: SendHandleProxy)
     case encryptionAuthenticity(String)
     case encryptionForwarder(String)
     case inviteAgain