[Bugfix:InstructorUI] Fix error in superuser email status page (Submitty#11438)

### Please check if the PR fulfills these requirements:

* [ ] Tests for the changes have been added/updated (if possible)
* [ ] Documentation has been updated/added if relevant
* [ ] Screenshots are attached to Github PR if visual/UI changes were
made

### What is the current behavior?
Closes Submitty#11430 

```
12:02:39 02/04/2025 - FATAL ERROR
Error (Code: 0) thrown in /usr/local/submitty/site/app/entities/email/EmailEntity.php (Line 95) by:
        return $this->term;


Message:
Typed property app\entities\email\EmailEntity::$term must not be accessed before initialization

Stack Trace:
#0 /usr/local/submitty/site/app/views/email/EmailStatusView.php(41): app\entities\email\EmailEntity->getTerm()
Submitty#1 unknown file(unknown line): app\views\email\EmailStatusView->renderStatusPage()
Submitty#2 /usr/local/submitty/site/app/libraries/Output.php(251): call_user_func_array()
Submitty#3 /usr/local/submitty/site/app/libraries/Output.php(220): app\libraries\Output->renderTemplate()
Submitty#4 /usr/local/submitty/site/app/libraries/response/WebResponse.php(43): app\libraries\Output->renderOutput()
Submitty#5 /usr/local/submitty/site/public/index.php(160): app\libraries\response\WebResponse->render()

USER: submitty-admin
URL: https://submitty.cs.rpi.edu//superuser/email_status_page?csrf_token=a73dc648cdff817faba856852b2c75d5&page=1
```

### What is the new behavior?

![now](https://github.com/user-attachments/assets/2a80c1aa-3a5c-4650-a91a-45d445cce076)
We can see the email status
### Other information?
How to Test:
login as superuser
send an email
check email status page

Author: Troy-bailan-King

site/app/entities/email/EmailEntity.php

@@ -92,11 +92,11 @@ public function getEmailAddress(): string {
     }
 
     public function getTerm(): ?string {
-        return $this->term;
+        return $this->term ?? null;
     }
 
     public function getCourse(): ?string {
-        return $this->course;
+        return $this->course ?? null;
     }
 
     /**