Add SonarCloud exceptions

Add SonarCloud rules to exclude false positives.

See https://sonarcloud.io/organizations/cern-cta/projects and https://docs.sonarcloud.io/advanced-setup/analysis-scope/.

GitHub actions are at https://github.com/cern-cta/CTA/actions

See also https://community.sonarsource.com/t/documentation-about-ignore-issues-seems-to-be-wrong-or-outdated/3353