[Assignments] Add a new condition to the "assignment rules"

Problem statement:

The rules for Assignment Categories only allow for "drop lowest score" without condition. This creates an inaccurate sense of mastery for students early in the semester, and often results in students completely skipping the final (capstone) assignment or missing a key unit/ the skills needed to complete the capstone. For example: A student thinks they've done a good job on research because their Assessment 3 was dropped and they didn't realize they didn't do well on it. Then Assessment 4 is even worse because they didn't spend time remediating their skills. OR: A student does great on the first 3 Assessments so decides to not bother with the last unit of the course.

Proposed solution:

Add to rules on Assignment Categories to not drop assignments unless minimum number of assignments have been submitted. For example: "drop the 1 lowest score if 4 assignments submitted". This would allow instructors to drop the lowest grade only if all assignments in the category were attempted. And/or at the end of the semester For my discipline, I need to ensure a minimum number of words written for transfer credit, but I would like to drop the lowest score to help focus on the student's average strengths (and take the pressure off for the high achievers). However, they still need to SUBMIT the word minimum for credit (even if I only use their highest scores to determine their grade).

User role(s):

instructor