ENH: finiteArea: apply modern IOobject traits

src/finiteArea/faMesh/faMeshTools/faMeshTools.C

...Area/d2dt2Schemes/EulerFaD2dt2Scheme/EulerFaD2dt2Scheme.C

...rea/finiteArea/d2dt2Schemes/faD2dt2Scheme/faD2dt2Scheme.C

...rea/finiteArea/d2dt2Schemes/faD2dt2Scheme/faD2dt2Scheme.H

...finiteArea/ddtSchemes/EulerFaDdtScheme/EulerFaDdtScheme.C

...Area/ddtSchemes/backwardFaDdtScheme/backwardFaDdtScheme.C

...s/boundedBackwardFaDdtScheme/boundedBackwardFaDdtScheme.C

...initeArea/finiteArea/ddtSchemes/faDdtScheme/faDdtScheme.C

...initeArea/finiteArea/ddtSchemes/faDdtScheme/faDdtScheme.H

...dtSchemes/steadyStateFaDdtScheme/steadyStateFaDdtScheme.C

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

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