show sender-user in message_view

flutter/lib/models/channel.dart

@@ -58,3 +58,29 @@ class ChannelWithSubscription {
     return jsonArr.map<ChannelWithSubscription>((e) => ChannelWithSubscription.fromJson(e as Map<String, dynamic>)).toList();
   }
 }
+
+class ChannelPreview {
+  final String channelID;
+  final String ownerUserID;
+  final String internalName;
+  final String displayName;
+  final String? descriptionName;
+
+  const ChannelPreview({
+    required this.channelID,
+    required this.ownerUserID,
+    required this.internalName,
+    required this.displayName,
+    required this.descriptionName,
+  });
+
+  factory ChannelPreview.fromJson(Map<String, dynamic> json) {
+    return ChannelPreview(
+      channelID: json['channel_id'] as String,
+      ownerUserID: json['owner_user_id'] as String,
+      internalName: json['internal_name'] as String,
+      displayName: json['display_name'] as String,
+      descriptionName: json['description_name'] as String?,
+    );
+  }
+}

flutter/lib/models/keytoken.dart

@@ -39,3 +39,32 @@ class KeyToken {
     return jsonArr.map<KeyToken>((e) => KeyToken.fromJson(e as Map<String, dynamic>)).toList();
   }
 }
+
+class KeyTokenPreview {
+  final String keytokenID;
+  final String name;
+  final String ownerUserID;
+  final bool allChannels;
+  final List<String> channels;
+  final String permissions;
+
+  const KeyTokenPreview({
+    required this.keytokenID,
+    required this.name,
+    required this.ownerUserID,
+    required this.allChannels,
+    required this.channels,
+    required this.permissions,
+  });
+
+  factory KeyTokenPreview.fromJson(Map<String, dynamic> json) {
+    return KeyTokenPreview(
+      keytokenID: json['keytoken_id'] as String,
+      name: json['name'] as String,
+      ownerUserID: json['owner_user_id'] as String,
+      allChannels: json['all_channels'] as bool,
+      channels: (json['channels'] as List<dynamic>).map((e) => e as String).toList(),
+      permissions: json['permissions'] as String,
+    );
+  }
+}

flutter/lib/models/user.dart

@@ -90,3 +90,20 @@ class UserWithClientsAndKeys {
     );
   }
 }
+
+class UserPreview {
+  final String userID;
+  final String? username;
+
+  const UserPreview({
+    required this.userID,
+    required this.username,
+  });
+
+  factory UserPreview.fromJson(Map<String, dynamic> json) {
+    return UserPreview(
+      userID: json['user_id'] as String,
+      username: json['username'] as String?,
+    );
+  }
+}