ENH: wallFunctions: use cornerWeights linear. Fixes #3218.
Summary
Use linear combinations of cornerweights.
Resolved bugs (If applicable)
Details of new models (If applicable)
No change.
Risks
- change to wall function behaviour for 'blender binomial' for cells with multiple wall faces.
- omegaWallFunction by default uses binomial so was affected. epsilonWallFunction by default uses stepwise which is not affected.