Handle large campaign generation

[Falinor]

Given a draft and a lot of housings :
Open a browser and render the HTML content using puppeteer.
The images are extracted from the HTML and saved for later.
The images are hidden in the HTML to avoid rendering them in the PDF.
Transform HTML to PDF and return the result as a PDFDocument.
Clean up the browser.
Merge the pages into a single PDF.
For each image, embed it in the PDF and reference it on each page at its correct position.
Save the final PDF.

Features

• Handles JPEG and PNG
• Handles variable positions for instance when there are one or more logo
• Avoids copying the same images over and over. Embed them once, reference them later
• Handles huge quantities using Node Streams