[ShadowServer] Verification

[pdamoune]

Proposed changes

• test
  • Add connector initialization test
• fix
  • Fix README logging info
  • Remove deprecated update_existing_data
  • requirements.txt - Add explicit library & versions
  • Add traceback & clean exit
• clean
  • Format README
  • Remove unused requirements.txt
  • Remove get_environment_variables & get_tlp_keys
  • Deprecate run_every for duration_period
  • fix README
  • Fix docker-compose.yml
• refactor
  • Move test folder outside of src & add tests-requirements.txt
  • Move Connector class to own file
  • Inject helper instead of instanciate in class
  • Implement BaseConnectorConfig
  • Implement ConnectorSettings
  • Implement Config in helper from the connector config
  • Inject config
  • Migrate run_every config
  • Migrate api_key, api_secret & marking config
  • Migrate incident config

Related issues

• https://github.com/OpenCTI-Platform/connectors/issues/3951

Checklist

• [ ] I consider the submitted work as finished
• [x] I have signed my commits using GPG key.
• [x] I tested the code for its functionality using different use cases
• [x] I added/update the relevant documentation (either on github or on notion)
• [x] Where necessary I refactored code to improve the overall quality

Further comments