unit and integration test improvement + explainer module

[technocreep]

simplified path_lib, added unit-tests

[pep8speaks]

@technocreep, my friend! There is something you should fix.

• In the file fedot_ind/core/architecture/experiment/TimeSeriesClassifierNN.py:

Line 34:39: W292 no newline at end of file

• In the file tests/unit/api/utils/test_configurator.py:

Line 1:1: F401 'pytest' imported but unused Line 2:1: F401 'fedot_ind.api.utils.configurator.IndustrialConfigs' imported but unused Line 64:9: W292 no newline at end of file

• In the file tests/unit/api/utils/test_saver_collections.py:

Line 25:85: E231 missing whitespace after ':' Line 62:36: E203 whitespace before ','

• In the file tests/unit/architecture/experiment/test_TimeSeriesClassifier.py:

Line 63:104: E231 missing whitespace after ',' Line 63:121: E501 line too long (121 > 120 characters) Line 168:1: W391 blank line at end of file

[codecov[bot]]

Codecov Report

Attention: 22 lines in your changes are missing coverage. Please review.

Comparison is base (870b4d0) 47.37% compared to head (d160a86) 71.01%. Report is 2 commits behind head on main.

Files	Patch %	Lines
...hitecture/experiment/TimeSeriesAnomalyDetection.py	28.57%	10 Missing :warning:
.../architecture/experiment/TimeSeriesClassifierNN.py	25.00%	3 Missing :warning:
...position/matrix_decomposition/dmd_decomposition.py	62.50%	3 Missing :warning:
...d/core/architecture/pipelines/anomaly_detection.py	0.00%	2 Missing :warning:
fedot_ind/api/utils/saver_collections.py	75.00%	1 Missing :warning:
...hitecture/experiment/TimeSeriesClassifierPreset.py	90.90%	1 Missing :warning:
fedot_ind/core/optimizer/IndustrialEvoOptimizer.py	0.00%	1 Missing :warning:
fedot_ind/tools/explain/explain.py	99.15%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #108 +/- ## =========================================== + Coverage 47.37% 71.01% +23.64% =========================================== Files 109 109 Lines 7059 7077 +18 =========================================== + Hits 3344 5026 +1682 + Misses 3715 2051 -1664 ``` | [Flag](https://app.codecov.io/gh/aimclub/Fedot.Industrial/pull/108/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aimclub) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/aimclub/Fedot.Industrial/pull/108/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aimclub) | `71.01% <91.09%> (+23.64%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=aimclub#carryforward-flags-in-the-pull-request-comment) to find out more.

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