Add Percentage of Items Passed distribution to the Pathway dashboard

User Story

As a course team member, I want to see a distribution of learners showing me the percentage of pathway items passed on the pathway dashboard, so that I have a quick sense of where the bulk of my learners are on their way to passing each course in the pathway.

Acceptance Criteria

Description a Percentage of Pathway Items Passed has been added to the Activity and Progress section of the Pathway Dashboard
Given I am a course team member with access to the Pathway Dashboard
When I view the Activity and Progress Section of the Pathway Dashboard
Then I see a Percentage of Items Passed (histogram) the shows % of pathway items passed out of all items in the enrolled pathway along the x-axis and N learners enrolled along y-axis for all currently filtered pathways

And if a single learner is enrolled in multiple pathways
Then I want to see that learner’s progress represented for each pathway run they are currently enrolled in

The issue names no files, tests, or entry points. Start by locating the Pathway Dashboard’s Activity and Progress section and tracing its pathway filters and learner-progress data. Done means the filtered dashboard shows a percentage-passed histogram and counts each learner separately for each enrolled pathway run.