gcongr attributes for lemmas up in the import chain

In this file we add gcongr attribute to lemmas in Lean.Init. We may add lemmas from other files imported by Mathlib/Tactic/GCongr/Core later.

theorem Mathlib.Tactic.GCongr.imp_mono {a b c d : Prop} (h₁ : c → a) (h₂ : c → b → d) : (a → b) → c → d

theorem Mathlib.Tactic.GCongr.and_mono {a b c d : Prop} (h₁ : a → c) (h₂ : a → b → d) : a ∧ b → c ∧ d