Project cleanup; removed unused resources and test classes. Fixed memory leak bug in DataFetcher.kt

app/src/main/res/layout/course_card.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<com.google.android.material.card.MaterialCardView
+<com.google.android.material.card.MaterialCardView xmlns:tools="http://schemas.android.com/tools"
     android:id="@+id/planCard"
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
@@ -63,7 +63,8 @@
                 android:layout_height="wrap_content"
                 android:layout_marginStart="2dp"
                 android:layout_marginEnd="2dp"
-                android:textColor="@color/colorText"/>
+                android:textColor="@color/colorText"
+                tools:ignore="HardcodedText" />
 
             <TextView
                 android:id="@+id/teacher"