General quality of life updates:
- Ticket contact edit: 'No one' should be logged when ticket isn't associated with any contact, rather than a blank space; also fix email content
- Ticket portal/guest: Only show 'Assigned to' if someone is actually assigned
- Ticket tasks: Don't allow adding/modifying tasks for tickets in a resolved state
- Portal contacts: Properly align word 'Contacts' in a similar way all other page headings are aligned
- Client PDF export/handover: Now opens in a new self-closing window