Overhaul UI: some minor improvements

See merge request !419

scroll automatically when necessary while moving a layer

See merge request !418

In the fitting view of the job view show a label with explaining text instead of empty space for jobs not ready for fitting

Layer editor improvements

See merge request !417

Overhaul ui: improve logging of fitting activiy

See merge request !416

Unit handling in layer oriented sample editor

See merge request !415

Remove PkgConfig dependence on Windows

See merge request !411

The module is used only under Windows.

Also, renamed `findPkgVersion` -> `find_pkg_version` for conformity with
CMake function names.

Integrate layer oriented sample editor into SampleView

See merge request !414