Create an indicator that we are low on space

[smlambert]

re: https://github.com/adoptium/ci-jenkins-pipelines/issues/254#issuecomment-1054314294

It may be beneficial to visually indicate or through the API response that we are running low or out of space on disk. Currently TRSS ability to respond to queries degrades with no obvious notice of underlying problem. If we can warn of the issue, then we can intervene (either to purge data or clean up disk space manually).

Discussion issue, what are options for doing this, do we want to have this feature?