Feature Preview Dataset file

In Datasets section for each dataset a Preview Button should be provided.

AC

• Clicking the button opens kind of Popover which contains a portion of the dataset (file)
• e.g we start with a text datei anfangen (and show a small portion of file).
• should not slow down the initial page rendering
• start with table format (i.e csv or .xlsx) - i.e 100 lines in total and show initially 20 lines and with a 'Load more' button we show 20 lines. We keep showing 'load more' when there are still at least 20 lines left.
• Dataset should be retrieved using DOI from Dariah repository (which url exactly) ?
• In case file is larger than 1 kB, then 1 kB from this file should be loaded.
• Scrolling through the pages of the file should be possible.
• Closing the preview should be possible