Commit 2022-03-24 10:12 355645e3

chore(data/polynomial/*): delete, rename and move lemmas (#12852)

• Replace eval_eq_finset_sum and eval_eq_finset_sum' with eval_eq_sum_range and eval_eq_sum_range' which are consistent with eval₂_eq_sum_range, eval₂_eq_sum_range' eval_eq_finset_sum, eval_eq_finset_sum'. Notice that the type of eval_eq_sum_range' is different, but this lemma has not been used anywhere in mathlib.
• Move the lemma C_eq_int_cast from data/polynomial/degree/definitions.lean to data/polynomial/basic.lean. C_eq_nat_cast was already here.