Issue 308 raw string support

[yilmazhasan]

Linked Issue

Closes #308

Description

The feature is to let toon output in a quoted way regardless of the type of the item, upon explicit argument is set.

Example:

const replacer: EncodeReplacer = (_k, v) => (typeof v === 'string' ? rawString(`"${v}"`) : v)
expect(encode({ id: '123' }, { replacer })).toBe('id: "123"')

Previously it was outputting 'id: 123', with this change it's possible to output 'id: "123"'

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)
• Performance improvement
• Test coverage improvement

Changes Made

• escapeString is now exported from toon-format/toon/index.ts
• RawString, rawString is implemented and exported from toon-format/toon/index.ts.

SPEC Compliance

• This PR implements/fixes spec compliance
• Spec section(s) affected:
• Spec version:

Testing

• Test cases added: raw-string.test.ts

• All existing tests pass

• Added new tests for changes

• Tests cover edge cases and spec compliance

Pre-submission Checklist

• My code follows the project's coding standards
• I have run code formatting/linting tools
• I have added tests that prove my fix/feature works
• New and existing tests pass locally
• I have updated documentation if needed
• I have reviewed the TOON specification for relevant sections

Breaking Changes

• No breaking changes
• Breaking changes (describe migration path below)

Additional Context

The issue #308 has been implemented with this PR.

It was a requirement to let toon to output quoted strings when replacer is customized.