More RepParams

This time to fix 2731 - where a rep param has a % in it. This text below breaks the rep param because it has a percentage in it.

Total summative assessment weighting % must be 100 (currently 52)

Part of the fix though is to make sure that multiple rep params work, so let's kind of replicate the above but with two things in it

The percentage % weighting should be 100 (currently 67) but some people will allow 80 (not many, only 3 organisations).