[CI] Using rules in CI as only is deprecated

See merge request !382

Add pages to doxygen

Closes #183

See merge request !379

- adds missing header to files
- unify header
- add SPDX (https://spdx.dev/) identifier to header (first step for getting REUSE https://reuse.software/ compliant)
- reworked doxgen

- uses awesome doxygen theme: https://jothepro.github.io/doxygen-awesome-css/

Adresses: #183

- adds wiki pages to doxygen page
- adds doxygen modules for production code and tests

Remove FFTW from 3rdParty folder.

See merge request !380

[GPU] Rework app SphereInChannel

See merge request !378

- fix error in the viscosity calculation
- remove confusing variable "length"
- add default config file that works in the docker container
- set initial velocity

CI and README changes.

See merge request !374

Bug fix get post collision distribution

See merge request !375

Merge branch 'develop' of https://git.rz.tu-bs.de/irmb/VirtualFluids into BugFixGetPostCOllisionDistribution

Write artifacts for multi gpu jobs only on failure. Removes clang build analyzer and include_what_you_use job, as the results are not used currently.

always call free method of interactors

See merge request !373

Add Alena to Author List

See merge request !372

Update CI Pipeline and sonar-project to new url.

See merge request !370

cleanup parameter

See merge request irmb/VirtualFluids_dev!369

Adds copyright headers and compiler information via buildInfo.h

See merge request irmb/VirtualFluids_dev!368