Remove json translations approach, add example for adding language

Signed-off-by: Sahil Kumar <[email protected]>

packages/stream_chat_flutter/lib/src/extension.dart

@@ -104,11 +104,7 @@ extension BuildContextX on BuildContext {
   double get textScaleFactor =>
       MediaQuery.maybeOf(this)?.textScaleFactor ?? 1.0;
 
-  String translate({
-    required String key,
-    required String defaultValue,
-  }) =>
-      StreamChatLocalizations.of(this)?.translate(key) ?? defaultValue;
+  StreamChatLocalizations? get translations => StreamChatLocalizations.of(this);
 }
 
 /// Extension on [BorderRadius]

packages/stream_chat_flutter/lib/src/message_text.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_markdown/flutter_markdown.dart';
 import 'package:stream_chat_flutter/stream_chat_flutter.dart';
 import 'package:stream_chat_flutter_core/stream_chat_flutter_core.dart';
+import 'package:stream_chat_flutter/src/extension.dart';
 
 /// Text widget to display in message
 class MessageText extends StatelessWidget {
@@ -29,6 +30,8 @@ class MessageText extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final texts = context.translations?.launchUrlError ?? 'defaultValue';
+    return Text(texts);
     final text = _replaceMentions(message.text ?? '').replaceAll('\n', '\n\n');
 
     final themeData = Theme.of(context);

packages/stream_chat_flutter/lib/src/stream_chat_localizations.dart

@@ -71,9 +71,6 @@ import 'package:flutter/widgets.dart';
 ///  * [GlobalStreamChatLocalizations], which provides material localizations
 ///    for many languages.
 abstract class StreamChatLocalizations {
-  ///
-  String? translate(String key);
-
   /// The `StreamChatLocalizations` from the closest [Localizations] instance
   /// that encloses the given context.
   ///
@@ -94,4 +91,6 @@ abstract class StreamChatLocalizations {
         context,
         StreamChatLocalizations,
       );
+
+  String get launchUrlError;
 }