Add cstring sub-library

[dreamer-coding]

Fossil XSDK Pull Request

Description

Adding a new sub-library for c string types, and string stream, this library starts with the essentials but will have more features overtime for suffocated string manipulation for the general purpose IO operations.

Testing

New test cases added to test new string, string stream functions and the new string and string stream classes.

Checklist

• Code follows the project's coding standards.
• Tests have been added or updated to cover the changes.
• Documentation has been updated to reflect the changes.
• The code has been reviewed by team members.
• All checks and tests pass.
• The license header and notices are updated where necessary.

License

This project is licensed under the Mozilla Public License - see the LICENSE file for details.