Add bbob-constrained

[y0z]

Contributor Agreements

Please read the contributor agreements and if you agree, please click the checkbox below.

• I agree to the contributor agreements.

Tip

Please follow the Quick TODO list to smoothly merge your PR.

Motivation & Description of the changes

Add the bbob constrained package for benchmarking.

Please merge optuna/optunahub#75 before merging this PR.

TODO List towards PR Merge

Please remove this section if this PR is not an addition of a new package.
Otherwise, please check the following TODO list:

• Copy ./template/ to create your package
• Replace <COPYRIGHT HOLDER> in LICENSE of your package with your name
• Fill out README.md in your package
• Add import statements of your function or class names to be used in __init__.py
• (Optional) Add from __future__ import annotations at the head of any Python files that include typing to support older Python versions
• Apply the formatter based on the tips in README.md
• Check whether your module works as intended based on the tips in README.md

[nabenabe0928]

LGTM!