Simplification failure for bra-ket swaps

[Krzmbrzl]

  SECTION("simplify") {
    SECTION("braket-symmetry") {
      auto expr = deserialize<ResultExpr>(
          "R1{a1;i1} = f{a1;i1}:A-S-S + f{i1;a1}:A-S-S");

      simplify(expr);

      REQUIRE_THAT(expr, EquivalentTo("R1{a1;i1} = 2 f{a1;i1}:A-S-S"));
    }
  }

This test fails, even though one would expect it to trivially pass. It is probably related to the fact that in this example the tensor network canonicalizer is not involved during canonicalization (single tensors are canonicalized by TensorCanonicalizer).