api [nfc]: Rename ApiNarrowStream to ApiNarrowChannel

Fixes parts of zulip#631

Author: Khader-1

lib/api/model/narrow.dart

@@ -34,14 +34,14 @@ sealed class ApiNarrowElement {
   };
 }
 
-class ApiNarrowStream extends ApiNarrowElement {
+class ApiNarrowChannel extends ApiNarrowElement {
   @override String get operator => 'stream';
 
   @override final int operand;
 
-  ApiNarrowStream(this.operand, {super.negated});
+  ApiNarrowChannel(this.operand, {super.negated});
 
-  factory ApiNarrowStream.fromJson(Map<String, dynamic> json) => ApiNarrowStream(
+  factory ApiNarrowChannel.fromJson(Map<String, dynamic> json) => ApiNarrowChannel(
     json['operand'] as int,
     negated: json['negated'] as bool? ?? false,
   );

lib/model/internal_link.dart

@@ -70,7 +70,7 @@ Uri narrowLink(PerAccountStore store, Narrow narrow, {int? nearMessageId}) {
     fragment.write('${element.operator}/');
 
     switch (element) {
-      case ApiNarrowStream():
+      case ApiNarrowChannel():
         final streamId = element.operand;
         final name = store.streams[streamId]?.name ?? 'unknown';
         final slugifiedName = _encodeHashComponent(name.replaceAll(' ', '-'));
@@ -149,7 +149,7 @@ Narrow? _interpretNarrowSegments(List<String> segments, PerAccountStore store) {
   assert(segments.isNotEmpty);
   assert(segments.length.isEven);
 
-  ApiNarrowStream? streamElement;
+  ApiNarrowChannel? streamElement;
   ApiNarrowTopic? topicElement;
   ApiNarrowDm? dmElement;
 
@@ -163,7 +163,7 @@ Narrow? _interpretNarrowSegments(List<String> segments, PerAccountStore store) {
         if (streamElement != null) return null;
         final streamId = _parseStreamOperand(operand, store);
         if (streamId == null) return null;
-        streamElement = ApiNarrowStream(streamId, negated: negated);
+        streamElement = ApiNarrowChannel(streamId, negated: negated);
 
       case _NarrowOperator.topic:
       case _NarrowOperator.subject:

lib/model/narrow.dart

@@ -76,7 +76,7 @@ class StreamNarrow extends Narrow {
   }
 
   @override
-  ApiNarrow apiEncode() => [ApiNarrowStream(streamId)];
+  ApiNarrow apiEncode() => [ApiNarrowChannel(streamId)];
 
   @override
   String toString() => 'StreamNarrow($streamId)';
@@ -108,7 +108,7 @@ class TopicNarrow extends Narrow implements SendableNarrow {
   }
 
   @override
-  ApiNarrow apiEncode() => [ApiNarrowStream(streamId), ApiNarrowTopic(topic)];
+  ApiNarrow apiEncode() => [ApiNarrowChannel(streamId), ApiNarrowTopic(topic)];
 
   @override
   StreamDestination get destination => StreamDestination(streamId, topic);