#1128: Generate list of all images

Minimal version of #45 is needed to begin this process: generate list of all figures in use by annotations (file name only). Nick can probably help us do this more easily from his data. Wait to see

This will then lead to work in #1129

I have a short-term solution for now:

• To create list of file names+URLs in each annotation, NJR used this tutorial: http://www.acrosswalls.org/ortext-datalinks/list-google-drive-folder-file-names-urls/
• This resulted in a Google Script Editor Project, GD folder file names
• A new spreadsheet is generated for each illustrations folder of annotation
• The results are copied into the master sheet, then the individual listing files are moved into dedicated folder in DCE GD folder