replace imports from pipelines/fourier_coefficients with mth5

- if tests pass we should be able to delete pipelines/fourier_coefficients

tests/synthetic/test_fourier_coefficients.py

@@ -1,26 +1,21 @@
 import unittest
 
 from aurora.config.config_creator import ConfigCreator
-from aurora.pipelines.fourier_coefficients import add_fcs_to_mth5
-from aurora.pipelines.fourier_coefficients import fc_decimations_creator
-
-# from aurora.pipelines.fourier_coefficients import read_back_fcs
 from aurora.pipelines.process_mth5 import process_mth5
 from aurora.test_utils.synthetic.make_processing_configs import (
     create_test_run_config,
 )
 from aurora.test_utils.synthetic.paths import SyntheticTestPaths
+from loguru import logger
 from mth5.data.make_mth5_from_asc import create_test1_h5
 from mth5.data.make_mth5_from_asc import create_test2_h5
 from mth5.data.make_mth5_from_asc import create_test3_h5
 from mth5.data.make_mth5_from_asc import create_test12rr_h5
-from mth5.timeseries.spectre.helpers import read_back_fcs
-
-# from mtpy-v2
-from mtpy.processing import RunSummary, KernelDataset
-
-from loguru import logger
 from mth5.helpers import close_open_files
+from mth5.timeseries.spectre.helpers import add_fcs_to_mth5
+from mth5.timeseries.spectre.helpers import fc_decimations_creator
+from mth5.timeseries.spectre.helpers import read_back_fcs
+from mtpy.processing import RunSummary, KernelDataset  # from mtpy-v2
 
 synthetic_test_paths = SyntheticTestPaths()
 synthetic_test_paths.mkdirs()