Clean up after regressors-2.0

[Mr-Geekman]

IMPORTANT: Please do not create a Pull Request without creating an issue first.

Before submitting (must do checklist)

• Did you read the contribution guide?
• Did you update the docs? We use Numpy format for all the methods and classes.
• Did you write any new necessary tests?
• Did you update the CHANGELOG?

Type of Change

• Examples / docs / tutorials / contributors update
• Bug fix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves an existing feature)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Proposed Changes

Look #559.

Related Issue

#559.

Closing issues

Closes #559.

[codecov-commenter]

Codecov Report

Merging #572 (04391ff) into master (5dbbc94) will decrease coverage by 32.67%.
The diff coverage is 0.00%.

@@             Coverage Diff             @@
##           master     #572       +/-   ##
===========================================
- Coverage   87.23%   54.55%   -32.68%     
===========================================
  Files         119      119               
  Lines        5712     5704        -8     
===========================================
- Hits         4983     3112     -1871     
- Misses        729     2592     +1863     

Impacted Files	Coverage Δ
etna/datasets/utils.py	34.78% <ø> (-65.22%)	⬇️
etna/loggers/wandb_logger.py	33.33% <0.00%> (ø)
etna/transforms/decomposition/trend.py	47.36% <ø> (-52.64%)	⬇️
etna/transforms/encoders/mean_segment_encoder.py	50.00% <0.00%> (-50.00%)	⬇️
etna/transforms/encoders/segment_encoder.py	50.00% <ø> (-50.00%)	⬇️
etna/transforms/math/add_constant.py	66.66% <ø> (-33.34%)	⬇️
etna/transforms/math/differencing.py	33.57% <0.00%> (-66.43%)	⬇️
etna/transforms/math/lags.py	83.33% <0.00%> (-16.67%)	⬇️
etna/transforms/math/log.py	60.86% <ø> (-36.96%)	⬇️
etna/transforms/math/power.py	100.00% <ø> (ø)
... and 86 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 5dbbc94...04391ff. Read the comment docs.

[alex-hse-repository]

Here, here, here we also need fixes