Cli skeleton

This provides a skeleton of the CLI. It is creating a `ProjectData` object and that's all for now.
Next steps shall include setup of processes, calling global assembly, and solving the resulting system of linear equations.
This way it looks like this:
```
 Brief USAGE: 
    /home/naumov/w/ogs/build/bin/ogs  [--] [--version] [-h] <PROJECT FILE>
```
so it is clear the project file is required.