Watch TLS certificates and reload on changes

[andsens]

See #9718 and #1678 Is your feature request related to a problem? Please describe. Short lived client certificates are the norm. fluent-bit does not reload TLS certificates when they are renewed and simply fails at shipping logs.

Describe the solution you'd like fluent-bit should reload the TLS configuration when any of the referenced files change.

Additional context People are doing all kinds of workarounds (e.g. https://github.com/fluent/helm-charts/pull/578) to do something that fluent-bit should do natively. Most other tooling I have encountered has done this for years. Two issues have been created for this over the last 6 years and they just went stale.
Please implement this.

[github-actions[bot]]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 5 days. Maintainers can add the exempt-stale label.

[andsens]

Not stale