Make error messages explain the error better for users

Hi,

It would be better for users if some of the error messaging in aXcelerate explained the error better.

For example, this is the error someone gets if they try to change the maximum attempt numbers on an assessment that is submitted.

If the error message was telling the user that:

"The request is denied as you can't adjust the maximum attempt numbers for assessments that have an 'in progress' or 'submitted' status"

then I think that would help more people to understand the error and what to do correctly to update what they wish to update.