Add support for format switching to the pluginLogger

[duffney]

What would you like to be added?

Include a setFormatter function in the internal/logger/logger.go (pluginLogger) package to allow switching between text, json, and logstash messages to match the functionality of the internal logger package.

See this conversation in PR #1258 for conext and this link for an example.

Anything else you would like to add?

No response

Are you willing to submit PRs to contribute to this feature?

• [X] Yes, I am willing to implement it.

[susanshi]

discussed in community meeting, please sync offline with @binbin-li