Slider component does not accurately update value if thumb image is large

Slider component does not accurately update the value if thumb image is large in size. The issue is that when a value range on the slider is clicked the thumb should match the associated value; however, because the thumb image is so large it does not snap correctly.

Regression:
This issue occurs in both 4.15.3 and 4.16 binary builds

1. Create a new project (No template or starter content needed)
2. Create a new Widget blueprint > Name it Widget_BP > Open Widget_BP
3. Recreate the setup from screenshot_01 (the top slider has all the default settings)
4. In the Event graph for the widget add an event "OnValueChanged" for the bottom slider and print the value
5. In the level blueprint > Create the widget Widget_BP and add it to the viewport
6. PIE and move the mouse to the end of the bottom slider and click

Result: The slider does not print a value of 1
Expected Result: The value printed should be 1 as its the end of the slider bar that was clicked