ENH: finiteArea: replace raw pointers with unique_ptr (#3107)

src/finiteArea/distributed/faMeshDistributor.C

src/finiteArea/distributed/faMeshDistributor.H

src/finiteArea/distributed/faMeshDistributorTemplates.C

src/finiteArea/faMatrices/faMatrix/faMatrix.C

src/finiteArea/faMatrices/faMatrix/faMatrix.H

src/finiteArea/faMesh/faMesh.C

src/finiteArea/faMesh/faMesh.H

src/finiteArea/faMesh/faMeshDemandDrivenData.C

src/finiteArea/faMesh/faMeshMapper/faAreaMapper.C

src/finiteArea/faMesh/faMeshMapper/faAreaMapper.H

src/finiteArea/faMesh/faMeshMapper/faEdgeMapper.C

src/finiteArea/faMesh/faMeshMapper/faEdgeMapper.H

src/finiteArea/faMesh/faMeshMapper/faPatchMapper.C

src/finiteArea/faMesh/faMeshMapper/faPatchMapper.H

src/finiteArea/faMesh/faMeshTopology.C

src/finiteArea/faMesh/faPatches/faPatch/faPatch.C

...ea/gradSchemes/leastSquaresFaGrad/leastSquaresFaVectors.C

...ea/gradSchemes/leastSquaresFaGrad/leastSquaresFaVectors.H

...anSchemes/gaussFaLaplacianScheme/gaussFaLaplacianScheme.C

...eArea/interpolation/edgeInterpolation/edgeInterpolation.C