fix(email): Emails are not sent in multiple cases

- fix(email): transactional emails are all not sent if `Use system wide (transactional) email settings` is disabled and no other email provide is setup on the Notifications page
- fix(email): no emails are sent if SMTP username and SMTP password are empty (which is the case in dev for example)
- fix(email): Wrong test email notification is used, causing the transactional email test notification to fail if no email provider is set up on the Notifications page.

app/Livewire/SettingsEmail.php

@@ -4,7 +4,7 @@
 
 use App\Models\InstanceSettings;
 use App\Models\Team;
-use App\Notifications\Test;
+use App\Notifications\TransactionalEmails\Test;
 use Illuminate\Support\Facades\RateLimiter;
 use Livewire\Attributes\Locked;
 use Livewire\Attributes\Validate;

app/Notifications/Channels/EmailChannel.php

@@ -12,8 +12,9 @@ public function __construct() {}
     public function send(SendsEmail $notifiable, Notification $notification): void
     {
         $useInstanceEmailSettings = $notifiable->emailNotificationSettings->use_instance_email_settings;
+        $isTransactionalEmail = data_get($notification, 'isTransactionalEmail', false);
         $customEmails = data_get($notification, 'emails', null);
-        if ($useInstanceEmailSettings) {
+        if ($useInstanceEmailSettings || $isTransactionalEmail) {
             $settings = instanceSettings();
         } else {
             $settings = $notifiable->emailNotificationSettings;
@@ -49,8 +50,8 @@ public function send(SendsEmail $notifiable, Notification $notification): void
                 $settings->smtp_port,
                 $encryption
             );
-            $transport->setUsername($settings->smtp_username);
-            $transport->setPassword($settings->smtp_password);
+            $transport->setUsername($settings->smtp_username ?? '');
+            $transport->setPassword($settings->smtp_password ?? '');
 
             $mailer = new \Symfony\Component\Mailer\Mailer($transport);
 

app/Notifications/TransactionalEmails/InvitationLink.php

@@ -16,9 +16,10 @@ public function via(): array
         return [TransactionalEmailChannel::class];
     }
 
-    public function __construct(public User $user)
+    public function __construct(public User $user, public bool $isTransactionalEmail)
     {
         $this->onQueue('high');
+        $this->isTransactionalEmail = true;
     }
 
     public function toMail(): MailMessage

app/Notifications/TransactionalEmails/ResetPassword.php

@@ -17,10 +17,11 @@ class ResetPassword extends Notification
 
     public InstanceSettings $settings;
 
-    public function __construct($token)
+    public function __construct($token, public bool $isTransactionalEmail)
     {
         $this->settings = instanceSettings();
         $this->token = $token;
+        $this->isTransactionalEmail = true;
     }
 
     public static function createUrlUsing($callback)

app/Notifications/TransactionalEmails/Test.php

@@ -8,9 +8,10 @@
 
 class Test extends CustomEmailNotification
 {
-    public function __construct(public string $emails)
+    public function __construct(public string $emails, public string $isTransactionalEmail)
     {
         $this->onQueue('high');
+        $this->isTransactionalEmail = true;
     }
 
     public function via(): array