Support the - character in the field names

[alirezanet]

Description

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context.

Fixes #219

Type of change

• New feature (non-breaking change which adds functionality)

Checklist

• I have performed a self-review of my code
• I have added tests that prove my fix is effective or that my feature works
• I have made corresponding changes to the documentation
• I have commented my code, particularly in hard-to-understand areas
• New and existing unit tests pass locally with my changes

[what-the-diff]

PR Summary

• Update to Tokenization Logic
  The modifications in Lexer.cs now allow hyphens (-) within field names. Previously, these characters caused issues during the tokenization process. This update improves our ability to interpret and process a greater variety of input data.

• Expanded Test Coverage
  A new test file named Issue219Tests.cs has been added to the system. This file includes specific test cases designed to check that field names containing hyphens are correctly analyzed and interpreted without causing errors. This addition enhances our verification process, ensuring our changes work as intended and increase system's reliability.