ENH: reduce number of methods for writing attributes

src/adiosFoam/adiosCoreWrite.H

src/adiosFoam/adiosCoreWriteAttr.C

src/adiosFoam/adiosCoreWriteTemplates.C

src/adiosFoam/adiosCoreWriteVar.C

src/adiosFoam/adiosReaderVarInfo.C

src/adiosFoam/adiosTraits.H