fix(localize): include legacy ids when describing messages (#36761)

Previously, we only displayed the new `$localize` id, which is not
currently what most people have in their translation files.
Until people migrate to the new message id system it is confusing
not to display the legacy ids.

PR Close #36761

packages/localize/src/utils/src/translations.ts

@@ -123,5 +123,7 @@ export function makeTemplateObject(cooked: string[], raw: string[]): TemplateStr
 
 function describeMessage(message: ParsedMessage): string {
   const meaningString = message.meaning && ` - "${message.meaning}"`;
-  return `"${message.messageId}" ("${message.messageString}"${meaningString})`;
+  const legacy =
+      message.legacyIds.length > 0 ? ` [${message.legacyIds.map(l => `"${l}"`).join(', ')}]` : '';
+  return `"${message.messageId}"${legacy} ("${message.messageString}"${meaningString})`;
 }

packages/localize/src/utils/test/translations_spec.ts

@@ -82,6 +82,13 @@ describe('utils', () => {
     it('should throw an error if there is no matching translation', () => {
       expect(() => doTranslate({}, parts`abc`))
           .toThrowError('No translation found for "2674653928643152084" ("abc").');
+      expect(() => doTranslate({}, parts`:@@customId:abc`))
+          .toThrowError('No translation found for "customId" ("abc").');
+      expect(
+          () => doTranslate(
+              {}, parts`:␟d42e3c2d3aa340581d42f53c46eb49ecb3d3beb4␟3896949568605777881:abc`))
+          .toThrowError(
+              'No translation found for "2674653928643152084" ["d42e3c2d3aa340581d42f53c46eb49ecb3d3beb4", "3896949568605777881"] ("abc").');
       expect(() => doTranslate({}, parts`:meaning|:abc`))
           .toThrowError('No translation found for "1071947593002928768" ("abc" - "meaning").');
     });