Refactor  model: overhaul starting and ending times of jobs (calculation and fitting)

See merge request !389

Fix crash if the details tab in the job view is clicked with no jobs present

See merge request !388

Remove unneeded include directices, remove one remaining usage of qInfo

Closes #137

See merge request !387

Introduce value descriptors

See merge request !386

Preparations for sample editor

See merge request !385

Remove obsolete code, resolves issue about Qt debug functions

See merge request !382

rm unused code

See merge request !383

CI/CD: Correct the folder for the MS-Windows package

See merge request !381

Moved the function to return a group info for form factors to FormFactorItems and deleted the now obsolete GroupInfoCatalog.*

The NSIS package includes all the required applications, examples, headers and libraries.
The NSIS build folder is set to `build/winpackage` to avoid littering the main
build directory.
The artifact paths are corrected to avoid the warnings at the end of the
GitLab-Runner build log:
```
WARNING: build/bin/Release/*.dll: no matching files
WARNING: build/bin/Release/*.exe: no matching files
```

Related to #133

rm unused functions

See merge request !380