Handle layer addition on acmi

Summary

1. When extruding an edge to a patch face make sure to extrude all the patch faces connected to that edge and cell. This will handle cyclicACMI (has duplicate patches - AMI and non-overlap)

2. handle fvMesh::readUpdate of cyclicACMI cases. These were clearing out the polyMesh level data so calculating with original, unadapted faceAreas so reporting open cells in e.g. checkMesh where there weren't any:

 ***Boundary openness (-0.0105688 -3.02042e-16 -7.87935e-18) possible hole in boundary description.
 ***Open cells found, max cell openness: 0.333333, number of open cells 61

Resolved bugs (If applicable)

Fixes #1988. Fixes #2036 (closed)

Risks

• cannot see any side-effects - if duplicate faces they both need extruding
• requires extra check for boundary edges so little overhead