fix(charts): geth logLevel

[quasystaty1]

Summary

adds verbosity flag to geth statefulset. The log level is set based on config.logLevel entry.
alternative approaches:

• Setting config.logLevel to a numeric value (as expected by Geth) with documentation for users. This keeps the configuration simple and consistent with other flags but diverges from our other charts.
• Templating the config value directly in values.yaml, which works but is not an ideal approach for maintainability.

Changes

• adds a new flag configuring geth log level.

Testing

Tested against a local cluster

Changelogs

No updates required.