Don't show `logMessage` messages to the user

[natebosch]

I was using log/show to correspond to echom/echo but the VSCode approach does not show "log" at all - they go somewhere else.

Probably need to enable logging to some file or something, maybe off by default but can be enabled?

[ainar-g]

Please do consider disabling logging by default. gopls, for one, logs some output on Error level, which borks up the output. See golang/go#33467.