Add script to format all source/header files in one go.

Administrator authored 4 years ago and Florian Uhlig committed 4 years ago

Add format check in GitLab CI configuration file.
Add CMake target for format checker .
Add neede CMake files and shell scripts.
Add label in GitLab CI configuration file such that it can be
properly sorted on CDash.
The checker is disabled till we format the complete code base.