Resolve "Notification asking students for feedback"

What does this mr do?

Send the students a notification when their request is approved to ask them for some feedback.

Screenshots

before

after

Does this MR meet the acceptance criteria?

• I have added a changelog entry to reflect the significant changes I made.
• Tests were created to test the feature.
• I have updated the documentation accordingly.
• I adhere to the style guide.

Closes #242 (closed)

Redo from !174 (closed)

src/main/java/nl/tudelft/ewi/queue/model/Notification.java

@@ -22,12 +22,19 @@ import java.util.Objects;
 
 import javax.persistence.*;
 
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
 import org.json.JSONObject;
 import org.springframework.format.annotation.DateTimeFormat;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
 @Entity
+@Getter
+@Setter
+@NoArgsConstructor
 public class Notification {
 	public final static String TIME_FORMAT = "dd/MM/yyyy HH:mm";
 
@@ -51,12 +58,11 @@ public class Notification {
 
 	private boolean read;
 
+	private String url;
+
 	@DateTimeFormat(pattern = TIME_FORMAT)
 	private LocalDateTime createdAt;
 
-	public Notification() {
-	}
-
 	public Notification(User user, Course course, String title, String message, int ttl) {
 		this.user = user;
 		this.course = course;
@@ -66,70 +72,22 @@ public class Notification {
 		this.createdAt = LocalDateTime.now();
 	}
 
-	public Long getId() {
-		return id;
-	}
-
-	public User getUser() {
-		return user;
-	}
-
-	public void setUser(User user) {
-		this.user = user;
-	}
-
-	public Course getCourse() {
-		return course;
-	}
-
-	public void setCourse(Course course) {
-		this.course = course;
-	}
-
-	public String getTitle() {
-		return title;
-	}
-
-	public void setTitle(String title) {
-		this.title = title;
-	}
-
-	public String getMessage() {
-		return message;
-	}
-
-	public void setMessage(String message) {
-		this.message = message;
-	}
-
-	public int getTtl() {
-		return ttl;
-	}
-
-	public void setTtl(int ttl) {
-		this.ttl = ttl;
+	public Notification(User user, Course course, String title, String message, int ttl, String url) {
+		this(user, course, title, message, ttl);
+		this.url = url;
 	}
 
-	public boolean isRead() {
-		return read;
+	public String getUrl() {
+		if (this.url == null) {
+			return "/notification/" + id;
+		}
+		return this.url;
 	}
 
 	public boolean isUnread() {
 		return !isRead();
 	}
 
-	public void setRead(boolean read) {
-		this.read = read;
-	}
-
-	public LocalDateTime getCreatedAt() {
-		return createdAt;
-	}
-
-	public void setCreatedAt(LocalDateTime createdAt) {
-		this.createdAt = createdAt;
-	}
-
 	public String toJSON() {
 		return new JSONObject()
 				.put("title", title)