Make bigger area for Play audio button

Problem/Motivation

Audio block have different clickable and "cursor pointer" areas. They should be the same.

Steps to reproduce

1) Create a lesson with Audio block
2) View the lesson and hover the right side of Play audio button, you should see pointer cursor
3) Click on the right side of Play audio button, audio won't play

Proposed resolution

Make the whole Play button clickable. When cursor has pointer styles - it should be clickable.