- Improves HTTP client hostname verification failure messages
- Adds "DiagnosticTrustManager" which logs certificate information
when trust cannot be established (hostname failure, CA path failure,
etc)
These diagnostic messages are designed so that many common TLS
problems can be diagnosed based solely (or primarily) on the
elasticsearch logs.
These diagnostics can be disabled by setting
xpack.security.ssl.diagnose.trust: false
Backport of: #48911