Add dtype assertion in test, fix dtype in lowering

[lsy323]

[DO NOT REVIEW UNTIL ALL FAILED CASES ARE FIXED]

• Add a new test to capture the return type of fmod
• Add assertion on dtype in test. Torch and TorchXLA2 should return both fp or integer results

The following tests failed with the new dtype assertion

FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_addmm_2 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_ceil_2 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_div_Scalar_mode_2 - AssertionError: True != False : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_floor_2 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_hardtanh_2 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_masked_fill_Scalar_2 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_reflection_pad1d_1 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_reflection_pad2d_1 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_reflection_pad3d_2 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_replication_pad2d_1 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_replication_pad3d_1 - AssertionError: False != True : Outputs are not both floating point or integer point.
FAILED test/test_core_aten_ops.py::TestCoreAtenOps::test_aten_trunc_2 - AssertionError: False != True : Outputs are not both floating point or integer point.