add options for logging learned lemmas and theory axioms

- add solver.axioms2files
  - prints negated theory axioms to files. Each file should be unsat
- add solver.lemmas2console
  - prints lemmas to the console.
- remove option smt.arith.dump_lemmas. It is replaced by solver.axioms2files

src/smt/seq_axioms.cpp

@@ -86,7 +86,7 @@ void seq_axioms::add_clause(expr_ref_vector const& clause) {
         justification* js =
             ctx().mk_justification(
                 ext_theory_eq_propagation_justification(
-                    th.get_id(), ctx().get_region(), 0, nullptr, 0, nullptr, n1, n2));
+                    th.get_id(), ctx(), 0, nullptr, 0, nullptr, n1, n2));
         ctx().assign_eq(n1, n2, eq_justification(js));
         return;
     }