fix [poker-evaluator] Card type too rigid

[rorymcgit]

Simplify Deck interface from rigid lowercase '2c', '2d' etc to key: string. Remove Card as a type (use string instead of keyof Deck). This is because poker-evaluator's public evalHand method accepts uppercase/lowercase/mixed-case strings as card inputs (converting to lowercase internally) so the current typing is too strict.

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If changing an existing definition:

• Provide a URL to documentation or source code which provides context for the suggested changes: toLowerCase() call, showing e.g. uppercase "Card" is valid
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[typescript-bot]

@rorymcgit Thank you for submitting this PR!

Pull requests from definition owners are typically merged after quick review from a DefinitelyTyped maintainer once the CI passes.

In the meantime, if the build fails or a merge conflict occurs, I'll let you know. Have a nice day!

[typescript-bot]

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