[Proposal] add c binding

[robberphex]

Dubbo have different language binding for different scenario:

• Dubbo Java for Java ecosystem.
• Dubbo Go for Go ecosystem.
• Dubbo Js for frontend scenario.
• Dubbo Python for AI/ML scenario.

Dubbo Rust should cover low level programming/system programming. At this system-programming scenario, It's required to provide C binding.
Rust has standard build tool chain, Dubbo Rust's C binding is easier to build than pure C implement of Dubbo.

So, Could we have add c binding in Dubbo Rust's tasks?