Add vRAM Total and vRAM % Used to parameters

Describe the feature / solution to your problem you'd like
I would like data related to vRAM total and vRAM % used to be available.

Describe alternatives you've considered / and or tested
I have tried to make the necessary code changes to make this work, but my python experience is limited.

Screenshots / photos & mockups of the Turing screen

Environment:

• Revision of this project [a6a0b3e], which is pretty recent. Future commits don't seem to change that function.
• OS with version [Windows 11 Pro]
• Python version [e.g. Python 3.12]
• Hardware [AMD CPU, GeForce 4090, 128GB RAM]

Additional context
Similar data is already available for CPU, which can be seen in the screenshot. I imagine the data is available, as the % used of vRAM has to be a data point if the graph works to display that percent. Additionally, if the vRAM used is known, and the vRAM % used is known (should be based on the GRAPH working), then you could do some math and determine the total amount of vRAM. That said, I would hope that there is a more direct way to get those metrics without having to calculate them, as rounding might make the results particularly terrible.

Start by tracing how the existing CPU parameters and GPU graph data are collected and exposed. Add vRAM total and vRAM percentage-used values alongside the existing monitoring parameters, and confirm both values are available for display without relying on rounded calculations.