Merging branch 'include_fix'  into 'main'.

See merge request !882

[selfContainedLinuxPack] Produce a self-contained self-extracting installer for BornAgain GUI on Linux

Merging branch 'selfContainedLinuxPack'  into 'main'.

A self-contained binary installer is produced for BornAgain GUI on Linux, and kept as a GitLab artifact.

The installer includes all the libraries required for BornAgain, its Python wheel, and additional libraries and plugins for the GUI (see `devtools/deploy/linux/adjust_pkg_linux.sh.in`).

The package is relocatable and self-extracting and does _not_ need root permissions.
The BornAgain build log is also added to the package for further info and debugging.

The package can be installed as the following (here, installation root path is chosen to be `/tmp/ba`):
```
$ chmod +x BornAgain-1.19.79-Linux.sh  # permit execution
$ ba_path='/tmp/ba'
$ mkdir $ba_path  # make a deliberate installation path
$ ./BornAgain-1.19.79-Linux.sh --exclude-subdir --skip-license --prefix=$ba_path
```
and then, the GUI can be executed:
```
$ cd $ba_path
$ ./bin/bornagain
```

The self-extracting installer provides also a small help for its options; use the following to see a detailed description of the available options:
```
$ BornAgain-1.19.79-Linux.sh --help
```

The documentation is accordingly updated.

Related to milestone %"0 Stable for installation and use"

See merge request !864

`qt.conf` files for Linux and MacOS must be distingished.

Merging branch 'sg2'  into 'main'.

See merge request !881

Merging branch 'sg1'  into 'main'.

See merge request !880

Merging branch 'i72'  into 'main'.

See merge request !877

Merging branch 'sf6'  into 'main'.

See merge request !879