Generic radio trait for hardware platforms

[ostrosco]

• Creation of initial traits to encapsulate radio operations, such as configuration, transmission, and receiving.
• In order to add generic trait bound support to the macro, the only way at the moment is to move the trait bounds down to the bottom so they can be captured with tt, otherwise generic trait bounds can't be parsed per rust-lang/rust#20272 which doesn't look like it's getting addressed anytime soon.
• Now trailing commas after the function are allowed in the create_node! macro to increase robustness when using the macro.