What type of report is this:

Description:

When a contact has an email but no firstname and no lastname, email is send to " " < the@email.com >.
When firstname and lastname are empty, the "To:" field should be email only, without " " and < >

Steps to test this PR:

1. Create a user without firstname and lastname
2. Send an email with mautic.
3. Check To header => To: " " < email@email.com > . It should be To: email@email.com to avoid display problem with most email clients