Ability to configure whether to grey out results of a filter in Advanced Roadmaps

Issue Summary

Provide the ability to toggle the greying out of issues that don't match a filter applied to an Advanced Roadmaps plan. 

Currently, if you have child issues that don't satisfy the filter, they are still displayed on the timeline without being greyed out. The ability to grey out these issues is not possible.

Steps to Reproduce

1. Create an Advanced Roadmaps plan
2. Create an Epic, Story and a sub-task below the Story
3. Transition the Story and Sub-task to DONE
4. Apply a Filter with the following;
   • Hierarchy is configured to show issues from Epic to Sub-task
   • Statuses are all 'To do' and 'In progress'
   • Tick the checkbox for 'Show full hierarchy'
5. Ideally, the Story and Sub-task should be greyed out, but they are not

Expected Results

Any child issues that don't meet the filter should be greyed out

Actual Results

The child issues such as Story and Sub-task are not greyed out

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available