🌱 Runner generation with optional configuration

[dax-uktc]

🍍 Allows for the Unity Test Runner to be generated by optionally
providing a configuration file specified as a command line argument.

This change is meant to allow unit test make scripts of custom projects
that utilize CMock generator to be able to conveniently enable optional
Unity features like, e.g., parameterized tests, when this framework
is integrated and managed by the custom project as a Git submodule
external dependency. That way local changes in configuration to
the third-party sources/scripts are avoided.

[dax-uktc]

Hi, there! Does anyone find this change indeed useful for making the integration of CMock/Unity into their projects even more convenient and streamlined? As hinted in the PR's description, our use case—which prompted the requested change—involves using the Unity test framework and the CMock mock/stub generator framework without customizing their respective sources and default configurations. This approach facilitates adopting (new feature/bug-fix) updates more easily, avoiding maintenance burden, and ensures consistent use of the provided standard functionality across various projects and development teams.

The requested interface change allows the scripted Unity Runner Generator creation to be customized by a third, configuration file, thus making the list of arguments to the command line a set of three complementary files that now feels complete and still remains practically flexible, as two of them may be optionally provided. We believe this offers real value to the development of the projects at hand because it provides a uniform, much more convenient and structured way to handle configuration issues and tailor the frameworks' behavior. We think the change is worth considering for implementation in CMock. I'd love to have your feedback on this minor, backward-compatible enhancement in the generation script's command-line invocation interface! Thank you!