Support for `global.registry` value in `logging-operator` Helm chart

[KateFiroozi]

Is your feature request related to a problem? Please describe.
While using private container registries, it is insufficient to override registry for multiple images multiple times in values.yaml. It is especially challanging for image components that are managed by operator itself. For example, fluentd or fluentd-drain-watch.

Describe the solution you'd like

• Add a global.registry value. Path it to all image reference in template files, unless overwritten specifically.
• Add image overrides for secondary components and pass those as arguments to the logging-operator (similar to opentelemetry-operator

Describe alternatives you've considered
Specifically include image full path duplicating registry for all secondary components.

Additional context
opentelemetry-operator does not support global.registry value.