`kstring` unit tests

[iWas-Coder]

Description

Please, include a summary of the changes and which issue(s) is/are fixed. Also include relevant motivation and context. Lastly, list any dependencies that are required for this change.

Issues:

• closes #23

  Motivation and context:

• Needed to test kstring module, as is one of the core components of the engine.

  Dependencies:

• N/A

Development and testing equipment

Development PC specs:

• CPU: R7 3800X 4.0GHz @ 1.05V

• RAM: 96GB DDR4 2400MT/s

• GPU: RTX 2060 SUPER

• OS: GNU/Linux (Gentoo)

• Glibc version: 2.37

• GCC version: 13.2.1

• Vulkan version: 1.3.261

  Please, describe the tests that you ran to verify your changes. Provide instructions so it can be reproducible. Also list any relevant details for your test configuration.

• All tests implemented and integrated here.

Type of change

• [ ] Bug fix (non-breaking change which fixes one or multiple issues).
• [x] New feature (non-breaking change which adds functionality).
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected).

Checklist:

• [x] I've read and comply with the contributing guidelines.
• [ ] I've tested my changes for new features and regressions on all supported operating systems.
• [ ] I've made corresponding changes to the documentation.
• [ ] I've checked my changes for any broken behaviour and/or any unjustified performance hits.
• [x] My changes generate no new warnings.
• [x] I've added tests that prove my fix is effective or that my feature works.
• [x] New and existing tests pass locally with my changes.