Tetrakis(1,2‐diaminoethane)dibromodiplatinum(II,IV) tetraperchlorate and bis(1,2‐diaminopropane)platinum(II) bis(1,2‐diaminopropane)diiodoplatinum(IV) tetraiodide: three‐dimensionally‐ordered and three‐dimensionally‐disordered Wolffram's salt analogues