Use Zap library for logging to support JSON

[nilebox]

Is your feature request related to a problem? Please describe. Currently log messages are written using the standard log package which prints messages in plain text, and doesn't support any customization, and is a problem when used in OpenTelemetry Collector.

Describe the solution you'd like Migrate to https://github.com/uber-go/zap for logging, and support passing a logger in the configuration / constructor.