Add configurable worker liveness probe with HTTP option

[RobertKeyser]

Description of Changes

Summary
Adds useHttpProbe toggle to switch worker liveness probes from the default celery inspect ping exec command to an HTTP GET against the in-process health check server (port 9000). The exec probe spawns a full Celery CLI process on every check, which may lead to issues when scaling workers.

Exposes initialDelaySeconds, periodSeconds, timeoutSeconds, and failureThreshold as configurable values under the workerConfiguration key. These were previously hardcoded or only partially configurable via fides.startupTimeSeconds / fides.healthCheckTimeoutSeconds.
Fully backwards compatible — defaults match current behavior.

Pre-merge Checklist

• All CI Pipelines Succeeded
• Documentation Updated
• Increment Applicable Chart Versions
• Relevant Follow-Up Issues Created
• Update the Fides chart CHANGELOG.md
• Update the Fides-minimal chart CHANGELOG.md