feat: avoid cooper case analysis for univariate polynomials (#7351)

This PR ensures cutsat does not have to perform case analysis in the
univariate polynomial case. That it, it can close a goal whenever there
is no solution for a divisibility constraint in an interval. Example of
theorem that is now proved in a single step by cutsat:
```lean
example (x : Int) : 100 ≤ x → x ≤ 10000 → 20000 ∣ 3*x → False := by
  grind
```