BUG Gale-Shapley

[Ama16]

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?

Proposed Changes

Closing issues

Closes #1097

[github-actions]

🚀 Deployed on https://deploy-preview-1110--etna-docs.netlify.app

[codecov-commenter]

Codecov Report

Merging #1110 (72a1a51) into master (da08758) will decrease coverage by 18.41%.
The diff coverage is 100.00%.

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@@             Coverage Diff             @@
##           master    #1110       +/-   ##
===========================================
- Coverage   86.86%   68.45%   -18.41%     
===========================================
  Files         170      170               
  Lines        9324     9321        -3     
===========================================
- Hits         8099     6381     -1718     
- Misses       1225     2940     +1715     

Impacted Files	Coverage Δ
etna/transforms/feature_selection/gale_shapley.py	100.00% <100.00%> (ø)
etna/commands/__main__.py	0.00% <0.00%> (-87.50%)	⬇️
etna/datasets/hierarchical_structure.py	22.01% <0.00%> (-75.23%)	⬇️
etna/libs/pmdarima_utils/arima.py	28.84% <0.00%> (-71.16%)	⬇️
etna/pipeline/assembling_pipelines.py	26.31% <0.00%> (-71.06%)	⬇️
etna/pipeline/mixins.py	31.42% <0.00%> (-67.62%)	⬇️
etna/analysis/outliers/hist_outliers.py	10.82% <0.00%> (-66.25%)	⬇️
etna/reconciliation/bottom_up.py	35.29% <0.00%> (-64.71%)	⬇️
etna/auto/optuna/config_sampler.py	32.25% <0.00%> (-62.91%)	⬇️
etna/models/deadline_ma.py	35.18% <0.00%> (-59.26%)	⬇️
... and 60 more

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[Mr-Geekman]

I think we should name it without get, because we don't use it as a function.