LightGBM

[dask] merge local_predict tests into other tests (fixes #3833) (#3842)

* Merge test_<est>_local_predict and test_<est> tests for Dask module ##3833

* Merge test_<est>_local_predict to test_<est> tests in dask module - refactor #3833

* Update test_classifier and rename variables resolves #3833

* rename variables resolves #3833

* manage precision error #3833

Co-authored-by: James Lamb <jaylamb20@gmail.com>