Pagination for images

[karindalziel]

The original site has pagination for images, but it's been broken for some time. This was likely pulled from the image corpus files, which I have added to data/scripts/data_ingest_helpers/lc.img.corpus.01.xml

I think the steps would be:

1: Use the above file to add previous and next links to the index
2: alter the previous/next code in the item view to also apply to images, but the progress bar should only apply to journal entries

[karindalziel]