Add Sleep Timer to Tasker Intent

### Description

The Tasker Control Playback option allows for skipping, changing speed and volume boost, but it doesn't have a Sleep Timer option.

I would like to be able to call StartTimer(mins) from Tasker to build a task that starts a 15 minute sleep timer anytime a podcast starts after 10pm.

### Screenshots or screen recording

_No response_

### Did you search for existing list?

- [x] I have searched for existing issues.

Start by locating the Tasker Control Playback intent handling and the existing sleep-timer implementation. Trace how playback actions are exposed to Tasker, then verify that StartTimer(mins) starts the requested timer when invoked from a Tasker task.

Written by the indexing model from the issue text.