Send informational CMake message(s) to stdout instead of stderr

[Codym48]

Is your feature request related to a problem? Please describe.
While executing the drac0-rc5 training exercises, I noticed on the first make prep call that the following message is printed to stderr

NOTE: Selected /home/cmartin/code/cFS/sample_defs/cpu1_cfe_es_startup.scr as source for cfe_es_startup.scr on cpu1

Describe the solution you'd like
This seems like an informational message that would be more appropriate for stdout than stderr.

Describe alternatives you've considered
Doing nothing.

Additional context
This is a bit of a trial balloon to feel out the cF* contribution process. I won't be offended if you close this with no action. Thank you for your hard work on this product and its outstanding documentation!

Requester Info
Cody Martin, personal contributor