Fix running Xvfb

See merge request !399

Selection descriptor

See merge request !393

... to have a std::bad_function_call exception in case of an uninitialized function pointer

Overhaul ui: update icon in job list and fix compilation issues

See merge request !394

CMake: Correct C++ Boost dependencies for Windows

With the new compiled Boost (1.77.0) on the Windows machine, there is no need to add zlib, bzip2, lzma, and zstd as extra dependencies for Boost. The compiled Boost binaries (on Windows) include `libboost_zlib` and `libboost_bzip2` (lzma and zstd are not required).

The Boost include and lib folders are cleanly separated from other libraries in order to make future updates easier.

The GitLab CI script for Windows is updated accordingly.

Related to issue #133

See merge request !391

The Windows build script is updated to use the newly compiled Boost 1.77.0.

* A minimal path is set in the beginning to avoid any unintended conflicts with
other libraries installed on the system.
* Timers are added to measure the elapsed times for building and testing.
* Verbosity of CPack is reduced.

The Boost include and lib folders are cleanly separated from other libraries in
order to make future updates easier.

Related to issue #133

CMake: Avoid executing tests during the build phase

See merge request !390

GoogleTest: `gtest_discover_tests` discovers tests by asking the _compiled test
executable_ to enumerate its tests. `PRE_TEST` delays test discovery until just
prior to test execution; this avoids calling the executables during the build
phase and hence, error messages like "Error running test executable".

Related to issue #133

Overhaul ui: job list

Closes #50

See merge request !392

With the new compiled Boost on the Windows machine, there is no need to add
zlib, bzip2, lzma, and zstd as extra dependencies. The compiled Boost binaries
include `libboost_zlib` and `libboost_bzip2` (lzma and zstd are not required).

Related to issue #133

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