Add Verbosity

Add print messages during the execution.
Verbosity should depend on a --verbose/--v parameter that is on by default.

- [ ] print used APIs status
- [ ] print targeted swagger endpoint
- [ ] print whether or not the swagger endpoint is reachable
- [ ] print if swagger json is valid json
- [ ] print generic "what is code doing" messages
- [ ] print targeted output path for produced files

List is subject to changes, and will probably be updated with new logs

No files, tests, or entry points are named. Start by locating the Python CLI entry point and its argument parsing, then trace the execution flow to identify where the requested status, endpoint, validation, and output messages belong; done means the listed messages appear under the default verbosity setting and can be controlled with the requested parameter.

Written by the indexing model from the issue text.