Remove L1 (base language) display from course info chips (#4378)

* Initial plan

* Remove L1 display from courses

Co-authored-by: ggurdin <46800240+ggurdin@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: ggurdin <46800240+ggurdin@users.noreply.github.com>

lib/pangea/course_creation/course_info_chip_widget.dart

@@ -92,8 +92,7 @@ class CourseInfoChipsState extends State<CourseInfoChips>
       children: [
         CourseInfoChip(
           icon: Icons.language,
-          text:
-              "${course!.baseLanguageDisplay} → ${course!.targetLanguageDisplay}",
+          text: course!.targetLanguageDisplay,
           fontSize: widget.fontSize,
           iconSize: widget.iconSize,
           padding: widget.padding,

lib/pangea/course_plans/courses/course_plan_model.dart

@@ -52,10 +52,6 @@ class CoursePlanModel {
       targetLanguageModel?.langCode.toUpperCase() ??
       targetLanguage.toUpperCase();
 
-  String get baseLanguageDisplay =>
-      baseLanguageModel?.langCode.toUpperCase() ??
-      languageOfInstructions.toUpperCase();
-
   /// Deserialize from JSON
   factory CoursePlanModel.fromJson(Map<String, dynamic> json) {
     return CoursePlanModel(