Even more compact (single-line) output for statusline use

i wanna display multi items for mult gpus (temp/ power draw/ vram use) in byobu status bar,

so could you please add a one line output mode, with query items selector.

ex. 
```
gpustat -q temp,power.draw,mem.used -> 
40, 40, 42 °C | 21 12 12 Watt | 6, 6, 6M 
```

if i have three nvidia cards


thank thee very much!