Node view should include available values

[jsoref]

If you are trying to resolve an environment-specific issue or have a one-off question about the edge case that does not require a feature then please consider asking a question in argocd slack channel.

Checklist:

• I've searched in the docs and FAQ for my answer: https://bit.ly/argocd-faq.
• I've included steps to reproduce the bug.
• I've pasted the output of argocd version.

Describe the bug

The graphs show requests, neighbors, and capacity. In theory a human can do the math to calculate availability, but in practice computers are much better

To Reproduce

1. Visit https://cd.apps.argoproj.io/applications/argo-cd?view=pods
2. Group by node
3. Hover over memory or cpu for a node

Expected behavior

Calculate available in addition to showing used and capacity

Screenshots

Version

{
    "Version": "v1.9.0+bb15a49",
    "BuildDate": "2021-02-06T00:55:32Z",
    "GitCommit": "bb15a4996e327fb27ad91f3f6fa24f831f7754e0",
    "GitTreeState": "clean",
    "GoVersion": "go1.14.12",
    "Compiler": "gc",
    "Platform": "linux/amd64",
    "KsonnetVersion": "v0.13.1",
    "KustomizeVersion": "v3.8.1 2020-07-16T00:58:46Z",
    "HelmVersion": "v3.5.1+g32c2223",
    "KubectlVersion": "v0.20.1",
    "JsonnetVersion": "v0.17.0"
}

Logs

Paste any relevant application logs here.