feat: AutoPlay Timer Override

[martin-affinitas]

Description
I would like to be able to temporarily override the AutoPlay timer for a slide to allow for variable slide timing.

Perhaps the AutoPlay time could be exposed to a slide. The Slide could save the current AutoPlay time value then reset it or set the time for the slide when it is displayed. The Timer would resume the user's value when the temp time is up.

It would be nice to be able to set autoplay on and the default time and Loop in the global configuration.