Improve navigation in unit tests
- Correctly display test results for test classes in a namespace
- Enable switching to the test source for tests without a test class and for tests with custom arguments
- Do not rely on the assumption that QTEST_MAIN or QTEST_GUILESS_MAIN is used to define the main function when deducing the test class. Instead use the last declaration in the main function that matches a typical test class.
- Fix and extend CTest unit tests (ctestfindsuites)
- Enable multi-selection of test cases and switch from single click to double-click for the activation