[GPU] Slip BoundaryConditions

Moved

• BoundaryConditions/Slip/SlipCompressible
• BoundaryConditions/Slip/SlipTurbulentViscosityCompressible

Deleted

• QSlipDev27-
• BBSlipDevComp27
• QSlipPressureDevCompTurbulentViscosity27
• QSlipGeomDevComp27
• QSlipNormDevComp27

Bookmarks

• MR: https://git.rz.tu-bs.de/irmb/VirtualFluids_dev/-/merge_requests/339
• commit: c0870a98
• parent: ecf329ae