Show GPU stats on the node utilization page

[SilinPavel]

Meterics

• GPU Utilization
• GPU Memory utilization

Dimension

• Time
• GPU ID (Model)

Node stats

Global metrics:

• Time GPU active (%% of node run time when GPU utilization was > 0)
• GPU utilization (Mean/Max/Min of all average GPUs utilization for the node run time)
• GPU memory (same as GPU utilization)

Global chart:

• GPU active (%% cards which have GPU utilization > 0)
• GPU utilization
• GPU memory

Heatmaps:

Same metrics as on the charts

• One line per GPU ID
• Each time point - gradient 0-100%
• Shown only when explicitly requested

Details:

• Details are shown for all metrics at a hovered timepoint
• GPU utilization and GPU memory metrics as heatmaps for the selected time point (semi-heatmap)
• Do not include GPU Active in the details
• Memory - show absolute value with %%

[NShaforostov]

Docs added via #3669 and located here.