Update grafana dashboards and add a script to pull them from upstream

[crssnd]

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What kind of PR is this?

Required: Mark one of the following that is applicable:

• [ ] kind/feature
• [x] kind/improvement
• [ ] kind/deprecation
• [ ] kind/documentation
• [ ] kind/clean-up
• [ ] kind/bug
• [ ] kind/other

Optional: Mark one or more of the following that are applicable:

[!important] Breaking changes should be marked kind/admin-change or kind/dev-change depending on type Critical security fixes should be marked with kind/security

• [ ] kind/admin-change
• [ ] kind/dev-change
• [ ] kind/security
• [ ] kind/adr

What does this PR do / why do we need this PR?

Created a script to pull the kube-prometheus-stacj grafana dashboards directly from the upstream repositories. Also, update the dashboards.

• Fixes #1759

Information to reviewers

I did a side-by-side comparison with the previous dashboards and the were pretty similar.

Checklist

• [ ] Proper commit message prefix on all commits
• Change checks:
  • [x] The change is transparent
  • [ ] The change is disruptive
  • [x] The change requires no migration steps
  • [ ] The change requires migration steps
  • [ ] The change upgrades CRDs
• Metrics checks:
  • [ ] The metrics are still exposed and present in Grafana after the change
  • [x] The metrics names didn't change (Grafana dashboards and Prometheus alerts are not affected)
  • [ ] The metrics names did change (Grafana dashboards and Prometheus alerts were fixed)
• Logs checks:
  • [x] The logs do not show any errors after the change
• Pod Security Policy checks:
  • [ ] Any changed pod is covered by Pod Security Admission
  • [ ] Any changed pod is covered by Gatekeeper Pod Security Policies
  • [x] The change does not cause any pods to be blocked by Pod Security Admission or Policies
• Network Policy checks:
  • [ ] Any changed pod is covered by Network Policies
  • [x] The change does not cause any dropped packets in the NetworkPolicy Dashboard
• Audit checks:
  • [x] The change does not cause any unnecessary Kubernetes audit events
  • [ ] The change requires changes to Kubernetes audit policy
• Falco checks:
  • [x] The change does not cause any alerts to be generated by Falco
• Bug checks:
  • [ ] The bug fix is covered by regression tests
• Config checks:
  • [ ] The schema was updated