Allow different SONAR token

[ArBridgeman]

Summary

In our public repositories, we use SONAR_TOKEN, but in our private ones, this secret comes from SONARQUBE_GITHUB.

This secret is used in https://github.com/exasol/python-toolbox/blob/main/.github/workflows/report.yml#L42.

We could add this to the BaseConfig and switch the template to use a Jinja variable. Relevant entry points:

• https://github.com/exasol/python-toolbox/blob/main/exasol/toolbox/config.py#L277
  We could add the SONAR_TOKEN_NAME either as property which is overridden or as an input into the BaseConfig class.
  We need for this to be added to the dictionary output of github_template_dict
• https://github.com/exasol/python-toolbox/blob/main/exasol/toolbox/templates/github/workflows/report.yml#L45
  We update this line to use the value added to the github_template_dict

Decision Points

• Decide if we want to hard-code the two allowed options & have users flip between them or just allow private repos to change the string.

To Dos

• Add way to change SONAR_TOKEN_NAME into BaseConfig; use the public SONAR_TOKEN as the default value. Then only private repos would need to override it.
• Modify the report.yml template to use the SONAR_TOKEN_NAME
• Modify the documentation to make it clear how to perform the needed action, likely on this page: https://exasol.github.io/python-toolbox/main/user_guide/features/github_workflows/github_project_configuration.html