Add CatBoost integration

[y0z]

Motivation

• Progress https://github.com/optuna/optuna/issues/4484

Description of the changes

• Add optuna/integration/catboost.py and its test from optuna/optuna to optuna-integration for isolation of the CatBoost integration

[codecov[bot]]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (7f4ee88) 33.37% compared to head (58a0953) 35.95%.

Files	Patch %	Lines
optuna_integration/catboost.py	92.10%	3 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #61 +/- ## ========================================== + Coverage 33.37% 35.95% +2.58% ========================================== Files 20 21 +1 Lines 827 865 +38 ========================================== + Hits 276 311 +35 - Misses 551 554 +3 ```

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[y0z]

Thank you for your feedback. I checked and applied your suggestions. Please confirm the changes.