Suggestion for room alias.

Rename `Mention` to `IntentionalMention` for clarity
Remove dead code, there is no intentional mention for Room or RoomAlias.
Rename `IntentionalMention.AtRoom` to `IntentionalMention.Room` to match Rust naming

features/share/impl/src/main/kotlin/io/element/android/features/share/impl/SharePresenter.kt

@@ -100,7 +100,7 @@ class SharePresenter @AssistedInject constructor(
                             matrixClient.getRoom(roomId)?.sendMessage(
                                 body = text,
                                 htmlBody = null,
-                                mentions = emptyList(),
+                                intentionalMentions = emptyList(),
                             )?.isSuccess.orFalse()
                         }
                         .all { it }