feat: apply E-matching for local lemmas in `grind` (#6582)

This PR adds support for creating local E-matching theorems for
universal propositions known to be true. It allows `grind` to
automatically solve examples such as:

```lean
example (b : List α) (p : α → Prop) (h₁ : ∀ a ∈ b, p a) (h₂ : ∃ a ∈ b, ¬p a) : False := by
  grind
```