The submissions are now divided into pages, max. 10 per page.
The latest submissions are also paginated.
I removed the 'download selected' button and added 'Download latest' and 'Download all' buttons.
The pipeline will build only when the corresponding method 'getSubmissionsByAssignmentFiltered()' from Labracore will be merged.
Closes #134 (closed) ( and #80 (closed))
