Burst file into individual pages.
Files written to /tmp with documentId prefix
todo:
The find operation will return an error for any file without x permission in /tmp directory
the current work around is to ignore stderr in this process.
Trying to grep filter 'Permission denied' has not yet worked.
Returns Promise<string[]>
list of file names, ex. page_1.pdf, page_2.pdf, etc...
Given a position and dimensions add the provided image to the provided pdf
pdf - the path to the original pdf
image - the image as a data uri
coordinates - pdf coordinates
dimensions - image dimensions
target - the page name after the document has gone through Stamp#_burst
out - the output file path