Add Javascript into Pdf

[Brian Lewis]

The current Pdf Surveys include Javascript. This is used, for example, in maintaining the row and column totals in enrolment grids.

It seems itext provides ways to do this (https://stackoverflow.com/questions/67364899/add-javascript-to-pdf-file-using-itext7-c-sharp)

Parheps rather than have this as a separate design-time task (ie in the construction of the empty template) that the javascri[t is added when the output file is generated.

[Brian Lewis]

Will add the javascript used in the pdf surveys to the assets/pdfSurvey folder for safekeeping.

[Brian Lewis]

task(pdfSurvey): add current javascript.js to assets

Resolves #1397 #1391

→ <<cset 9a5a63f0fa31>>

[Brian Lewis]

feat(pdf): demonstration of loading javascript validators

Resolves #1397

→ <<cset f25cfb3ed0b2>>