generate_from_arb has been moved to intl_translantion library (#9255)

* generate_from_arb has been moved to intl_translantion library

* fixed typo

* added missing intl dependency

* Regenerated language files with latest intl script

* Added version to intl_translations

* added isolate min version constraint

examples/stocks/lib/i18n/regenerate.md

 To rebuild the i18n files:
 
 ```
-pub run intl:generate_from_arb \
+pub run intl_translation:generate_from_arb \
   --output-dir=lib/i18n \
   --generated-file-prefix=stock_ \
   --no-use-deferred-loading \

examples/stocks/lib/i18n/stock_messages_all.dart

@@ -29,15 +29,24 @@ MessageLookupByLibrary _findExact(localeName) {
 
 /// User programs should call this before using [localeName] for messages.
 Future initializeMessages(String localeName) {
-  initializeInternalMessageLookup(() => new CompositeMessageLookup());
   var lib = _deferredLibraries[Intl.canonicalizedLocale(localeName)];
   var load = lib == null ? new Future.value(false) : lib();
-  return load.then((_) =>
-      messageLookup.addLocale(localeName, _findGeneratedMessagesFor));
+  return load.then((_) {
+    initializeInternalMessageLookup(() => new CompositeMessageLookup());
+    messageLookup.addLocale(localeName, _findGeneratedMessagesFor);
+  });
+}
+
+bool _messagesExistFor(String locale) {
+  var messages;
+  try {
+    messages = _findExact(locale);
+  } catch (e) {}
+  return messages != null;
 }
 
 MessageLookupByLibrary _findGeneratedMessagesFor(locale) {
-  var actualLocale = Intl.verifiedLocale(locale, (x) => _findExact(x) != null,
+  var actualLocale = Intl.verifiedLocale(locale, _messagesExistFor,
       onFailure: (_) => null);
   if (actualLocale == null) return null;
   return _findExact(actualLocale);

examples/stocks/pubspec.yaml

@@ -3,7 +3,9 @@ dependencies:
   flutter:
     sdk: flutter
   intl: '>=0.14.0 <0.15.0'
+  intl_translation: '>=0.14.0 <0.15.0'
   http: '>=0.11.3+12'
+  isolate: '>=1.0.0'
 
 dev_dependencies:
   flutter_test: