Add Function to BCArray to validate node for collision.

See merge request !386

Free PrecollisionIntercator in Destructor

See merge request !384

Add reuse badge

See merge request !387

Adds REUSE compliance

See merge request !385

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

Remove virtual function call in lbm kernel

See merge request !376

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

Add Licenses for cuda_samples

See merge request !381

Add doxygen link to readme.

See merge request !383

[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