Use a more restricted log receiver in cm.rkt

@mflatt can you take a look at this?

The problem I want to solve is to be able to conditionally send log messages from TR to DrRacket based on whether DrRacket is listening for tooltip messages.

Currently, the `cm-accomplice` logger will catch *all* compile-time log messages (though it only cares about a subset of those) because the expression `(make-log-receiver accomplice-logger 'debug)` creates a log receiver that catches all messages `'debug` and higher (i.e., all of them) since the `accomplice-logger` is not restricted by name.

This PR restricts the logger to only listen for the relevant ones, so that TR can more reliably check if DrRacket is listening or not.