Improve teacher/ta view

• The table for submissions shows IDs (useless for teachers) and group IDs (useless for teachers), remove
• The button to view submission should be first in the table, otherwise it falls off the screen and its not apparent there are more columns
• Add column where it shows whether the submission was reported (by any review)
• Add better visual indicator that we can go to the right in the table (?)
• When not using groups, showing both group name and submitted by makes no sense.