[Merged by Bors] - feat(RingTheory/Polynomial/HilbertPoly): the definition and key property of Polynomial.hilbertPoly p d for p : F[X] and d : ℕ, where F is a field.

[Merged by Bors] - feat(RingTheory/Polynomial/HilbertPoly): the definition and key property of Polynomial.hilbertPoly p d for p : F[X] and d : ℕ, where F is a field. #70889