Add WALE and dynamic Smagorinsky/SEV SGS models

[ia267]

Add the remaining models from Incompact3D: WALE, dynamic Smagorinsky, dynamic SEV.

Scope

• WALE eddy viscosity (no wall damping needed - correct near-wall scaling built in)
• Dynamic Smagorinsky (Germano-Lilly procedure: test filter + least-sqaures coefficient), dynamic SEV
• Selectable via the same config as Add Smagorinsky LES with wall damping #321
• Scalar/buoyancy SGS diffusivity (turbulent Prandtl number)

Acceptance criteria

• WALE and dynamic variants selectable from config, both backends
• Validated on TGV at Re=5000 vs the DNS dissipation-rate

Dependencies

Needs #321