Fridge model record class added

src/main/java/ntnu/idatt2016/v233/SmartMat/model/Fridge.java

+package ntnu.idatt2016.v233.SmartMat.model;
+
+/**
+ * Fridge is a record class representing a fridge in the system.
+ *
+ * @author Anders
+ * @version 1.0
+ * @since 04.04.2023
+ *
+ * @param fridgeId
+ * @param groupId
+ */
+public record Fridge(long fridgeId, long groupId) {
+}