Add option to specify/limit compiler C standard in Compiler Parameters

At the moment, the C standard is not explicitly set in the makefile, so the compiler's default implementation is used. The latest C-compiler in openSUSE Tumbleweed cannot compile generated code any more since it uses C23 by default, where "bool" is defined.

In the Makefile generation, the standard should be limited to C99, but it should be configurable