Add styles to tables in details-pane

- added styles to tables in details-pane
Merge branch 'dev' into feature/styleguide-details-pane-table
use detail-pane-table style for relations table
Use generalised table styles for relations and attachments.
add titles for attachments and relations table headers.
Merge pull request #1717 from opf/feature/styleguide-details-pane-table