Add literal types

[Lipen]

This PR adds proper support for different TS literal types: string/number/boolean. Each literal class is now represented as a separate data class under the sealed interface EtsLiteralType.

[Copilot]

Pull Request Overview

This PR refactors TypeScript literal type support by replacing the generic EtsLiteralType with specific literal type classes for different value types. The refactoring changes the single EtsLiteralType data class into a sealed interface with three implementing data classes: EtsStringLiteralType, EtsNumberLiteralType, and EtsBooleanLiteralType.

• Converts EtsLiteralType from a data class to a sealed interface
• Adds three specific literal type implementations with type-safe value storage
• Updates the visitor pattern to handle each literal type separately
• Enhances JSON deserialization to properly handle different literal value types

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
Type.kt	Refactors literal type hierarchy from single class to sealed interface with three implementations
Convert.kt	Updates JSON-to-type conversion to map literal values to appropriate type classes
EtsFromJsonTest.kt	Adds comprehensive test coverage for all literal type variants

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[github-actions]

Test Results

  217 files  ±0    217 suites  ±0   15m 57s ⏱️ +5s
  737 tests +8    725 ✅ +8  12 💤 ±0  0 ❌ ±0 
2 005 runs  +8  1 955 ✅ +8  50 💤 ±0  0 ❌ ±0 

Results for commit f3655cb. ± Comparison against base commit 0a50288.