Unused Attribute

[kvkpraneeth]

Before submitting a pull request, make sure you satisfy all of the following points:

• [x] Give as much detail as possible on what is included within the pull request As discussed in the issue: https://github.com/juanmanzanero/fastest-lap/issues/21

Extra changes added in engine.hpp to check the __unused__ attribute on certain parameters, to ensure optional parameters don't trigger the exception.

• [x] Make sure that new additions are not already present in the project
• [x] If it contains source code, comply with the coding guidelines
• [x] Add new tests for new features
• [x] Run and pass the tests using GitHub's workflows

[juanmanzanero]

Ok thank you! On to fixing the broken tests..