fixed a serious bug in PushPresentationByIsomorphism
LeftSubmodule( [ ], R ) and RightSubmodule( [ ], R ) now return the zero ideal
declared and installed \* for [ IsRingElement, IsHomalgModuleElement ]
fixed PrimaryDecompositionOp and RadicalDecompositionOp for zero ideals
homalg generators now support a component ConvertTransitionMatrix

affected:
. NewHomalgGenerators
. UnionOfRelations
. \* for [ IsHomalgMatrix, IsHomalgGenerators ]
LeadingModule now checks for RP!.LeadingIdeal

and AffineDegree now uses LeadingModule as a last choice
(this makes AffineDegree computable with MAGMA)
HilbertPoincareSeries and HilbertPolynomial now support IsDivisionRingForHomalg