Issue when setting memory_mode as OutplaceEmphasis() in DICG.

[WenjieXiao-2022]

In the /test/decomposition_invariant.jl, when run the DICG standard run for ProbabilitySimplex oracle, if we specify the memory_mode as OutplaceEmphasis(), the starting point x0, which is obatined by compute_extrem_point(), will be ScaledHotVector() type.

In OutplaceEmphasis() mode, x0 will not be converted into SparseArrays but compute_extrem_point() and compute_inface_extrem_point() both require x to be SparseArrays. Therefore it throws error as !match.

Some kind of check and conversion might be necessary if it is OutplaceEmphasis() and starting point is not SparseArrays for ProbabilitySimplex oracle.

[matbesancon]

that's a good point, we rarely test with OutplaceEmphasis TBH because one can often work around for immutable types, it would be worth a PR still