Add `verbose` logs to Codec Registration Checker Compiler Plugin

[LukaszKontowski]

For now, it is possible for users to set a

ashCodecRegistrationCheckerCompilerPlugin / ashCompilerPluginVerbose := true

However, --verbose option is not even parsed by the plugin itself and is not used. We should add working --verbose mode for the plugin and add some debug-like logs when --verbose is enabled.

Remeber to update docs/GUIDE.md after adding working --verbose mode