Custom case cli bug, refactoring and README updates.

[Sheharyar570]

This PR includes the following changes.

1. Fixed custom_case key error in parameters dict in CLI command.
2. Refactored command options, replaced no-custom-dataset-use-shuffled and no-custom-dataset-with-gt with skip-custom-dataset-use-shuffled and skip-custom-dataset-with-gt for consistency.
3. Added custom case related command options information.
4. Added instruction to include custom_case while adding the CLI support for the client.

[Sheharyar570]

/assign @XuanYang-cn

[sre-ci-robot]

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