Description of the new feature/enhancement

In #4018, word navigation for selection and accessibility is merged into this mess:

• GetWordEnd (with accessibilityMode flag)
• GetWordStart (with accessibilityMode flag)
• MoveToNextWord
• MoveToPreviousWord

There has to be a way to combine all of these into just 2 functions (or 4 with an accessibilityMode flag). Unfortunately, doing so at the time could have resulted in breaking Selection for the sake of Accessibility (if one was not careful). So here's a work item to refactor that and make it look waaaaay better.

Proposed technical implementation details (optional)

There's a good amount of repeated code/concepts throughout these functions. I think we should just rely on making the function return a bool and have an in/out param.