Improving the peer review "padlet"-view

[oseppala]

The padlet-inspired view in rubyric is cumbersome to use and makes it hard to read and give feedback.

Ideas are welcome

[khanetor]

I have flat out the layout to have 1 submission per line.
The member names should be shown instead of group id.
Instead of showing button with very long filename, filename is now in tooltip.

[khanetor]

The update is in #5b56929. Could you take a look?