* remove duplicate icons from icon example
* create initial forward and back button classes
* add logic for back/forward buttons on click
* change icon used based on option passed into player
* move logic from forward and back buttons into one component
* add jsdoc comments for clarity
* create initial test file
* refactor button logic into separate files
* update skip button example and add test files
* test both the forward and backward buttons
* test handleClick fns for both forward and backward btns
* update skip buttons example
* update jsdocs for skip backward and forward buttons
* make control text accessible and use seekableEnd/Start when skipping forward/back
* update font version to use updated icons
* set control text only if config is valid
* add link to sandbox page & use localization
* update translations needed
