* Added base for minimal variance sampling booster

* Implemented MVS booster with support for multioutput targets, deterministic execution on small datasets/

* Updated documentation and fixed some linting errors

* fixed python sklearn documentation, tryed to fix R Cran CI

* Second attempt to fix R pipeline

* Fixed R package build for windows and linting error

* Revert "Fixed R package build for windows and linting error"

This reverts commit d50769e

* Revert "Revert "Fixed R package build for windows and linting error""

This reverts commit f531f3a.

* Fixed some documentation

* Fixed intendation error in mvs.hpp, fixed some windows build issues, added spinx version upper bound

* Fixed intendation error in mvs.hpp, fixed some windows build issues, added spinx version upper bound

* Update requirements_base.txt

* Update R-package/src/Makevars.in

Co-authored-by: James Lamb <[email protected]>

* Update R-package/src/Makevars.win.in

Co-authored-by: James Lamb <[email protected]>

* Added MVS booster support for dask tests

* Moved CalculateThresholdSequential to array_args.h and renamed it to CalculateThresholdMVS

* Added cpp tests for ArrayArgs::CalculateThresholdMVS and ArrayArgs::Partition.

* Fix linter errors in test_dask.py

* Fixed UB in ArrayArgs::Partition, when it is called with one element.

* Fixed linter errors

* Added more cpp tests and fixed linting errors

* Fixed linting errors

* Updated R-package documentation
Updated documentation
Updated test_mvs_threshold_search.cpp
Added parallel computation of regularized absolute value term.
Added new mvs parameter from constant.

* Updated MVS Lambda algorithm

* Updated documentation, MVS::GetLambda, MVS::GetThreshold, updated MVS::ResetConfig

* [ci] fix current `master` fails with graphviz-related error (#5068)

* Update test_windows.ps1

* Update .appveyor.yml

* Update test_windows.ps1

* Update .appveyor.yml

Co-authored-by: James Lamb <[email protected]>
Co-authored-by: Nikita Titov <[email protected]>
Co-authored-by: Yu Shi <[email protected]>

Co-authored-by: James Lamb <[email protected]>

Co-authored-by: James Lamb <[email protected]>

Co-authored-by: James Lamb <[email protected]>

Co-authored-by: James Lamb <[email protected]>

Co-authored-by: James Lamb <[email protected]>

Co-authored-by: Guolin Ke <[email protected]>

Co-authored-by: James Lamb <[email protected]>

…mvs_dev