Power on/off should have optional confirmation dialog

[pedrolamas]

Is your feature request related to a problem? Please describe.

Right now, all the [power] elements will work without any confirmation whatsoever, something that might be a problem to some

Describe the solution you'd like:

I think that an optional confirmation popup for the [power] elements would be ideal, just like it currently shows for the host reboot/shutdown options.

Affected users and/or setups:

All users would benefit from this, but specifically those that have the printer and other devices (such as controllable LEDs) on the [power] configuration elements.

Additional Context:

[pedrolamas]

This has been implemented a while back, so we can close this now!