[REVIEW] Obey initialize_embeddings parameter in B-H tSNE

[zbjornson]

Fixes #2549

This is tricky to test with certainty because this t-SNE implementation isn't deterministic, but I'm fairly certain it's correct. The top row of #2980 (comment) uses it.

[GPUtester]

Can one of the admins verify this patch?

[GPUtester]

Can one of the admins verify this patch?

[codecov-io]

Codecov Report

Merging #3011 into branch-0.17 will increase coverage by 0.56%.
The diff coverage is 96.15%.

@@               Coverage Diff               @@
##           branch-0.17    #3011      +/-   ##
===============================================
+ Coverage        58.39%   58.95%   +0.56%     
===============================================
  Files              143      143              
  Lines             8897     9008     +111     
===============================================
+ Hits              5195     5311     +116     
+ Misses            3702     3697       -5     

Impacted Files	Coverage Δ
python/cuml/thirdparty_adapters/adapters.py	88.44% <95.74%> (+6.20%)	⬆️
...l/_thirdparty/sklearn/preprocessing/_imputation.py	62.50% <100.00%> (-4.05%)	⬇️
python/cuml/thirdparty_adapters/__init__.py	100.00% <100.00%> (ø)
python/cuml/pytest_benchmarks/test_bench.py	100.00% <0.00%> (ø)
python/cuml/common/array.py	97.72% <0.00%> (+0.01%)	⬆️
python/cuml/metrics/_ranking.py	98.61% <0.00%> (+0.03%)	⬆️
python/cuml/preprocessing/encoders.py	95.18% <0.00%> (+0.07%)	⬆️
...on/cuml/_thirdparty/sklearn/preprocessing/_data.py	63.45% <0.00%> (+0.12%)	⬆️
python/cuml/naive_bayes/naive_bayes.py	92.69% <0.00%> (+0.16%)	⬆️
...ing/text/stem/porter_stemmer_utils/suffix_utils.py	90.47% <0.00%> (+0.23%)	⬆️
... and 33 more

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[dantegd]

Changes lgtm