Feature Request: Add toPascalCaseKeys, toKebabCaseKeys, and toConstantCaseKeys #1982

While es-toolkit contains camelCase, snakeCase, pascalCase, kebabCase, and constantCase, it currently only has toCamelCaseKeys and toSnakeCaseKeys. It would be good to have the equivalent object keys conversion functions for pascalCase, kebabCase, and constantCase, if only for completeness reasons.

In terms of real world usage, I know DOMPurify uses constant case for part of its config object keys (and one of my packages manually does the conversion for both the type and runtime for now).