implement batch_normalization

[lkarthee]

Implemented batch_normalisation, divide_no_nan and few fixes for imports.

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[lkarthee]

Batch Normalisation Test Results

└─▶ KERAS_BACKEND=mlx SKIP_APPLICATIONS_TESTS=True pytest keras/layers/normalization/batch_normalization_test.py
=========================================================================== test session starts ============================================================================
platform darwin -- Python 3.12.2, pytest-8.1.1, pluggy-1.4.0 -- keras/.venv/bin/python3.12
cachedir: .pytest_cache
rootdir: keras
configfile: pyproject.toml
plugins: cov-5.0.0
collected 26 items

keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_bachnorm_ignore_masked_values0 PASSED                                           [  3%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_bachnorm_ignore_masked_values1 PASSED                                           [  7%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_bachnorm_ignore_masked_values2 PASSED                                           [ 11%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_bachnorm_ignore_masked_values3 PASSED                                           [ 15%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_bachnorm_ignore_masked_values4 PASSED                                           [ 19%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_bachnorm_ignore_masked_values5 PASSED                                           [ 23%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_bn_basics PASSED                                                                [ 26%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness0 PASSED                                                             [ 30%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness1 PASSED                                                             [ 34%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness10 PASSED                                                            [ 38%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness11 PASSED                                                            [ 42%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness12 PASSED                                                            [ 46%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness13 PASSED                                                            [ 50%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness14 PASSED                                                            [ 53%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness15 PASSED                                                            [ 57%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness2 PASSED                                                             [ 61%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness3 PASSED                                                             [ 65%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness4 PASSED                                                             [ 69%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness5 PASSED                                                             [ 73%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness6 PASSED                                                             [ 76%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness7 PASSED                                                             [ 80%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness8 PASSED                                                             [ 84%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_correctness9 PASSED                                                             [ 88%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_input_fully_masked0 PASSED                                                      [ 92%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_large_value_within_autocast_scope PASSED                                        [ 96%]
keras/layers/normalization/batch_normalization_test.py::BatchNormalizationTest::test_trainable_behavior PASSED                                                       [100%]

============================================================================ 26 passed in 3.99s ============================================================================

[fchollet]

Thank you for the PR -- it looks good!

There are several refactors we need to perform right now when we merge master (e.g. we use from keras import tree now, and the code is located at keras/src/ rather than keras/). But they're out of scope for this PR, we'll handle that in the next merge.