Assignment: Add warning about students falling into Default group if group submissions are enabled but not required

Prerequisites: Login as admin Create a course C Create three users T, S1 and S2 Enrol user T into course C as teacher Enrol users S1 and S2 into course C as student Login as user T Go to course C Create two groups A and B Add user S1 to groups A and B Make sure that user S2 is not a member of any group User story 1: Create an assignment activity Set "Students submit in groups" to yes Set "Require group to make submission" to yes Set "Grouping for student groups" to none (which is the default) Confirm: On the assignment main page, there is a warning box saying "The setting 'Require group to make submission' is enabled and some users are either not a member of any group, or are a member of more than one group, so are unable to make submissions." User story 2: Create an assignment activity Set "Students submit in groups" to yes Set "Require group to make submission" to no (which is the default) Set "Grouping for student groups" to none (which is the default) Confirm: On the assignment main page, there is a warning box saying "The setting 'Student submit in groups' is enabled and some users are either not a member of any group, or are a member of more than one group. Please be aware that these students will submit as members of the 'Default group'."