Add vGPU allocatable warning banner

[torchiaf]

Summary

Fixes https://github.com/rancher/dashboard/issues/10989

Occurred changes and/or fixed issues

It adds a banner to provide guidelines about vGPUs allocation.

Technical notes summary

Areas or cases that should be tested

Areas which could experience regressions

Screenshot/Video

Checklist

• [x] The PR is linked to an issue and the linked issue has a Milestone, or no issue is needed
• [x] The PR has a Milestone
• [x] The PR template has been filled out
• [x] The PR has been self reviewed
• [x] The PR has a reviewer assigned
• [x] The PR has automated tests or clear instructions for manual tests and the linked issue has appropriate QA labels, or tests are not needed
• [x] The PR has reviewed with UX and tested in light and dark mode, or there are no UX changes