Log: libcrmservice: downgrade failed action messages

Previously, we would often get duplicate log messages for failed actions,
from the service library and again from its callers.

Now that the service library tracks and provides exit reasons, callers can log
sufficient detail with better context, so downgrade the library's messages to
info level or lower. Similarly, avoid duplicate logs of process output.

Certain messages (such as out-of-memory) remain at higher severity.