Plugin logs are hard to use

[rholshausen]

Currently, plugin logs to standard output are captured and logged via the calling frameworks logging. This can make it hard to separate from normal logs and pact logs, esp at trace level.

For me the biggest issue when start using plugin is I can't see its logs, so I really don't know what is going on. For now my understanding about plugins is a bit better so I don't have to read its logs, but I am always afraid of it.

Here is the related thread https://pact-foundation.slack.com/archives/C047TCR7B6W/p1679760157876359

Also:

The logging point is a good one. It used to be possible to use RUST_LOG when using the plugin for consumer tests and we would see all of the child_process logs but this seems to have stopped. Being about to log to a file would be nice, capturing any stdout from the plugin process. This would also make the logs easier to read/parse as using the tracing crate in both the plugin and the driver means the child_process lines are quite noisy.