Improve display of status table.

[danmarsden]

When a student views and edits a rating allocation activity the Status table can be quite long - especially when a large number of choices are available (we have a client looking at having up to 600 options in one activity)

Before an activity opens - it shows all the options in the "Rateable Choices" row, and repeats all the options again in the "your rating" row with the status "unrated"

This table also shows when editing the choices - so we see the 2 lists with all the choices, and then underneath we see the form that allows the options to be chosen.

I propose:

1. When a user is giving a rating - the status table should not be displayed at the top - just the form.

2. When the activity is not open, on the initial view page - we just show a list of available choices. - we don't display "your choices" because they are irrelevant.

3. When the activity is open and the user has made some choices - we only show the "your rating" style row.

4. When the list of choices is higher than a a certain number (I might set this to something arbitrary like 10) - we don't display the choices on first page load, but we hide the full list behind a show more style JS - I'm currently thinking of modeling this on the "submission comments" row in moodle's assignment plugin - it shows the text " > Comments (5)" - where "5" is the number of comments - we'd have something similar like " > Choices (X) " where "X" is the number of choices available to the user in the activity.

Keen to hear if you have any objections on this - but I'll submit a PR with these for you to review.

[danmarsden]

I've sent through PR's for 1-3 above - if you're happy with those, and your'e also happy with the approach in 4) I'll put together another PR for that later.

thanks!