[Audio] Allow multiple urls for [p]play

### What component of Red (cog, command, API) would you like to see improvements on?

Audio

### Describe the enhancement you're suggesting.

i.e `xplay song 1; song 2; song 3; song 4`

`Queued song 1; song 2; song 3; song 4`

### Anything else?

Which file would I need to look into for changes like these? Any guidance or insights?

```
audio_dataclasses.py
audio_logging.py
converters.py
equalizer.py
errors.py
manager.py
sql_statements.py
utils.py
```