Merge poster and papers from iPRES 2014

[anjackson]

Report:

It looks like you're double counting the actual poster and the paper for a poster as 2 different things: https://lite.datasette.io/?url=https%3A%2F%2Fraw.githubusercontent.com%2Fdigipres%2Fdigipres-practice-index%2Fmain%2Freleases%2Fpractice.db#/practice/publications?_facet=year&_facet=license&_facet=language&_facet=type&_facet_array=keywords&_facet_array=creators&_facet_array=institutions&_facet_size=8&_searchmode=raw&_sort_desc=year&creators__arraycontains=Paul+Wheatley&type=poster

Inspecting the data, 2014 has 12 items with titles ending 'Poster (Text) ', and these records should be merged with the corresponding Poster records. Not clear how to do this at present.