Add iGPU usage stats

[Unspec7]

Is your feature request related to a problem? Please describe.
I'm currently using frigate in an unprivileged LXC, and so I cannot see iGPU stats. I was wondering if iGPU stats could be included in the CPU/drive/etc card? Primarily interested in the Render/3D and Video utilization percentages. Even better would be if it could be displayed in the existing CPU usage graph, which by default only contains CPU usage and IO delay.

Thanks!

Describe the solution you'd like
Able to see GPU utilization percentages

Describe alternatives you've considered
N/A

Additional context
N/A

Sensors output

From "intel_gpu_top -J":

{ "period": { "duration": 36.071383, "unit": "ms" }, "frequency": { "requested": 0.000000, "actual": 0.000000, "unit": "MHz" }, "interrupts": { "count": 0.000000, "unit": "irq/s" }, "rc6": { "value": 99.998680, "unit": "%" }, "power": { "GPU": 0.000000, "Package": 4.944216, "unit": "W" }, "imc-bandwidth": { "reads": 624.670112, "writes": 59.454119, "unit": "MiB/s" }, "engines": { "Render/3D/0": { "busy": 0.000000, "sema": 0.000000, "wait": 0.000000, "unit": "%" }, "Blitter/0": { "busy": 0.000000, "sema": 0.000000, "wait": 0.000000, "unit": "%" }, "Video/0": { "busy": 0.000000, "sema": 0.000000, "wait": 0.000000, "unit": "%" }, "VideoEnhance/0": { "busy": 0.000000, "sema": 0.000000, "wait": 0.000000, "unit": "%" } }, "clients": { "4293430945": { "name": "ffmpeg", "pid": "1536351", "engine-classes": { "Render/3D": { "busy": "0.000000", "unit": "%" }, "Blitter": { "busy": "0.000000", "unit": "%" }, "Video": { "busy": "0.099742", "unit": "%" }, "VideoEnhance": { "busy": "0.000000", "unit": "%" } } } } }