Have Python Evergreen tests print standard output on failure

Currently most Python test case failures in Evergreen don't show useful information on the console. It's necessary to spawn an instance and look at the content of stderr and stdout to see that information. We should enhance our Evergreen runner to output the information to the console.

On Linux a command like: find WT_TEST -name std*.txt ! -empty -printf "\n%p\n" -exec cat {} \; will show the content we'd like to see. Maybe we can fold this into Python so that we end up with a solution that's built into our test runner and platform agnostic.