Add kebab-case notation support to typia transformer library

[Copilot]

This PR implements kebab-case notation transformers following the existing pattern for camel, pascal, and snake case transformations. The implementation enables seamless conversion between kebab-case API responses and TypeScript-friendly camelCase properties.

Problem

Many REST APIs return data in kebab-case format (e.g., user-name, email-address), but accessing these properties in TypeScript requires cumbersome string indexing:

// Before: clunky string indexing required
const firstName = apiResponse["first-name"];
const streetName = apiResponse["home-address"]["street-name"];

Solution

This PR adds complete kebab-case notation support with the same API as existing notation transformers:

interface UserProfile {
  firstName: string;
  emailAddress: string;
  homeAddress: {
    streetName: string;
    zipCode: number;
  };
}

// API response in kebab-case
const apiResponse = {
  "first-name": "John",
  "email-address": "john.doe@example.com", 
  "home-address": {
    "street-name": "Main Street",
    "zip-code": 12345
  }
};

// Convert to TypeScript-friendly camelCase
const userProfile = typia.notations.kebab<UserProfile>(apiResponse);
// Now access normally: userProfile.firstName, userProfile.emailAddress

// With validation
const validated = typia.notations.validateKebab<UserProfile>(apiResponse);
if (validated.success) {
  console.log(validated.data.homeAddress.streetName);
}

// With assertion
const asserted = typia.notations.assertKebab<UserProfile>(apiResponse);

// Type checking
const checked = typia.notations.isKebab<UserProfile>(apiResponse);

Implementation Details

• Type System: Added KebabCase<T> utility type that converts all object keys to kebab-case
• String Conversion: Enhanced NamingConvention namespace with bidirectional kebab conversion functions
• Transformer Integration: Updated CallExpressionTransformer to map all kebab notation functions
• API Completeness: Supports all transformation variants: kebab, assertKebab, isKebab, validateKebab, and their factory functions

Conversion Examples

The implementation handles all common naming convention conversions:

• camelCase → kebab-case: firstName → first-name, socialSecurityNumber → social-security-number
• kebab-case → camelCase: first-name → firstName, social-security-number → socialSecurityNumber
• snake_case → kebab-case: first_name → first-name
• PascalCase → kebab-case: FirstName → first-name

Edge cases are properly handled including empty strings, single characters, prefix preservation, and complex acronyms.

Fixes #1548.

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