Suppress unwanted warnings in GeoModelIO

This MR adds proper logging to GeoModelDBManager and suppress unwanted warning messages from being printed to std::cout independently of the log level.

In particular, it suppresses the warnings about missing tables for new GeoModel nodes/classes in older .db files: we want to be free to develop and add new classes without invalidating the earlier DBs.

The MR also removes old and unused code.

This MR closes #115 (closed)

added GeoModelIO label

changed the description

added 3 commits

• f34f1731 - 1 commit from branch main
• 75bab9e8 - Add set log level method and remove old, unused code (old destructor)
• 5d333ae9 - Add proper logging, suppress unwanted messages to cout, remove old variables

Compare with previous version

mentioned in merge request !355 (merged)

merged