Migrate to new SonarQube issue structure

[fniessink]

SonarQube docs:

• https://docs.sonarsource.com/sonarqube/latest/user-guide/clean-code/#:~:text=There%20are%20three%20software%20qualities,with%20a%20level%20of%20severity.
• https://docs.sonarsource.com/sonarqube/latest/setup-and-upgrade/release-upgrade-notes/

Tasks:

• Replace the severity parameter values with low/medium/high and use the impactSeverites parameter for the api/issues/search endpoint
• Drop the issue type parameter
• Add a "clean code attribute" parameter and use the cleanCodeAttributeCategories parameter for the api/issues/search endpoint
• Add a "software quality" parameter and use the impactSoftwareQualities parameter for the api/issues/search endpoint

The new issue structure is available in SonarQube >= 10.2. Document this.