Forward button does not work when $wait timeout is fired

[saurabhdaware]

Steps to reproduce

• Create a talk with $wait10s somewhere in the transcript.
• When 10 seconds pause is fired, try pressing forward button or backward button

Expected Behavior

• When Forward or Backward is pressed, the timeout should be canceled.

Problem?

when the talk discovers $wait10s it calls a function await wait(10000) which is promisified version of setTimeout (the function is defined in scripts/helpers.js). When it fires it waits for the promise to resolve to continue. Meanwhile, if you press forward it will go forward but after promise is resolved it will go back to the previous slide.