feat(ui): sliders should indicate frame where a fiducial is placed
Description
When placing fiducials on a particular slice/frame, it may be hard to retrieve it, especially when there are many frames. Adding some "indicator" on the sliders may help to locate frames of interest.
Functional specifications
The slider will visually change with vertical lines matching the color of the fiducial on the slider to recognize the frame and slice index number where the fiducial has been added.
Technical specifications
Adjust the code within the adaptor/fiducials section by incorporating a QPaintEvent to handle the rendering of vertical markers on a slider. Retrieve the color of each fiducial, its position on the image (specifically the slice index number), and the orientation of the frame to properly display the lines .
Test plan
Manually test with the Sight_Viewer application.