* SingleExecutor: added TODOs
* test `SingleExecutor` with files and project
* SingleExecutor: process markup files after code when scanning project
* TestSingleExecutor: generate scoped files before calling executor
* CI-unixish.yml: added `--output-on-failure` to CTest call
* helpers.cpp: improved error reporting in `~ScopedFile()`
* use unique filenames in executor tests to avoid collisions
* fixed `functionStatic` selfcheck warnings
Daniel Marjamäki
Oliver Stöneberg