Add WARNING and INFO mgs to clarify routing module selection

[cmaynard-ngwpc]

The newly added code to provide better detail when importing a python module exposed a sequence in the routing code that first tries to import the ngen_routing module, which has been deprecated, then the nwm_routing, which is successful. Added EWTS log entries to better reflect this in the logs and show the correct module is imported.

Additions

• Additional LOG messages to report the routing module import attempt
• Additional LOG message to indicate action in response to the ngen_routing module not found.

Changes

• Update LOG message wording.
• Changed a couple LOG messages from DEBUG to INFO to show how the WARNING was address in the log.

Checklist

• PR has an informative and human-readable title
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows project standards (link if applicable)
• Passes all existing automated tests
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output)
• Placeholder code is flagged / future todos are captured in comments
• Project documentation has been updated (including the "Unreleased" section of the CHANGELOG)
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