Fix unanswerable complex numbers exercises

fix #42389; fix #42381; fix #42377; fix #42376; fix #42371; fix #42369;
fix #42366; fix #42362; fix #42360; fix #42357; fix #42355; fix #42352;
fix #42347; fix #42338; fix #42335; fix #42328; fix #42315; fix #42311;
fix #42306; fix #42303; fix #42297; fix #42295; fix #42293; fix #42292;
fix #42287; fix #42284; fix #42275; fix #42274; fix #42270; fix #42323;
fix #42329; fix #42322; fix #42390; fix #42368; fix #42348; fix #42336;
fix #42331; fix #42300; fix #42288; fix #42286; fix #42330; fix #42308;
fix #42289

Test plan: Test the following seeds locally:
http://localhost:8000/exercises/multiplying_and_dividing_complex_number_polar_forms.html?seed=120&problem=multiply-cplx&debug
http://localhost:8000/exercises/multiplying_and_dividing_complex_number_polar_forms.html?seed=79&problem=divide-cplx&debug
http://localhost:8000/exercises/powers_of_complex_numbers_1.html?debug&problem=0&seed=180

Auditors: cbhl