feat(environments): add RLCards environments for Project loong board game following the multi-step Env for RL purposes

[duanyiqun]

Description

Describe your changes in detail (optional if the linked issue already contains a detailed description of the changes).

Introduce new environments for RLCards games (Blackjack, Leduc Hold'em) and Doudizhu, enabling possible reward collection for the Project Loong, board game domain.

These environments include game-specific logic, state formatting, and action handling.

Environment files are:

• https://github.com/duanyiqun/camel/blob/project_loong_rlcards/camel/environments/rlcards_env.py

The environments are following the multi-step env and the tic-tac-toe example as discussed with @hallerite

Examples are provided to demonstrate usage and interaction with the environments.

https://github.com/duanyiqun/camel/blob/project_loong_rlcards/examples/environments/rlcards_example.py

Checklist

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• I have read the CONTRIBUTION guide (required)
• I have linked this PR to an issue using the Development section on the right sidebar or by adding Fixes #issue-number in the PR description (required)
• I have checked if any dependencies need to be added or updated in pyproject.toml and uv lock
• I have updated the tests accordingly (required for a bug fix or a new feature)
• I have updated the documentation if needed:
• I have added examples if this is a new feature

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