widget: power consumption HUD widget

### Problem to solve

While the information is available at the battery widget, I'd like to see something we could overlay on top of the video, that would be useful for when you are focused on the video and/or navigating

### Desired approach

I'm thinking of something that grows with the power consumption, and maybe turns redder as it grows, too.
I bet @ES-Alexander can think of something cool

### Additional context

_No response_

### Prerequisites

- [x] I have checked to make sure that a similar request has not already been filed or fixed.

related to https://github.com/bluerobotics/cockpit/issues/343

Start by reviewing the existing battery widget and the related issue #343 to understand how power-consumption data is exposed. Then determine how an overlay on the video should represent increasing consumption and changing color; done means the HUD widget visibly reflects power use while navigating or watching video.

Written by the indexing model from the issue text.