[D4C] Add handling to better surface cloud-defend unit state failure errors

[mitodrummer]

Elastic Defend (endpoint) is peaking into to this data and adding error panels inside the "input" dropdown on the right of the "agent status page". Our integration won't surface our error payloads, so this ticket is to track adding something similar to what endpoint does for cloud_defend.

It might be helpful to include a link to a "troubleshooting" section of our integration readme, and then specific "component" errors could have their own resolutions we point the user towards. e.g uncommenting capabilities

[mitodrummer]

Looks like the fleet team has this on their radar: #154634

[norrietaylor]

This should be ready for testing in 8.9