Add activity completion indicators to the course index

For Moodle 4.0 course index:

To help learners track their progress and have an easy overview of which activities have been completed and which are still outstanding we will add activity completion indicators to the course index (the green or empty circles in front of the activity names as shown below).

In the course index we want to reflect only 3 states of activity completion to reduce complexity. Below is the mapping of what the course index activity completion indicators should show for existing activity completion statuses.

New course index completion indicator	Corresponding activity completion report indicator	Meaning
		Activity not complete.
		Activity completed and no passing grade applies. For example: passing grade does not apply to this activity type, or passing grade has not been set as part of the activity's completion criteria.
		Completed, activity has passing grade which was achieved.
		Activity not completed and completion not possible. For example: all quiz attempts have been used without achieving the passing grade.