Invoice generation improvements

We've followed up on feedback to deliver minor improvements to invoice formatting and major improvements to the PDF generation process.

Key changes

The invoice view in the client experience and on your preview show an unpaginated view of the invoice
The timelog groups entries by phase and provides a more compact view of the entry details
Attachment images only scale down as much as necessary to allow them to fit on the page
All invoice tables maintain headers whenever they break across pages in the PDF view