Use `TerritoryDecompositionByWreathCycle` instead of `WreathProductDecomposition`.

[FriedrichRober]

Currently we use a WreathProductDecomposition in our internal methods, which blows up the storage space of a wreath product element w with m component to O(m^2) many base components. It would be much more convenient to use a TerritoryDecompositionByWreathCycle, which adds a storage of O(m) many integers (as permutations or singeltons) and access the components of the element directly via this decomposition. A Wreath Cycle is then uniquely identified by the element w and the top cycle permutation or singleton from the TerritoryDecompositionByWreathCycle.