Allow injecting structs and impls in comptime

[Thunkar]

Problem

It's not possible to inject structs or impls in Quoted code returned by annotations. It's explicitly disallowed and the compiler returns: Unsupported statement type to unquote

Happy Case

Something like this should be possible:

#[generate_interface]
fn my_fn() {}


comptime fn generate_interface(f: FunctionDefinition) {
  quote {
    struct MyFnInterface {}
    
    impl MyFnInterface {
     fn properties () {...}
   }
  }
}

Workaround

None

Workaround Description

No response

Additional Context

No response

Project Impact

Blocker

Blocker Context

No response

Would you like to submit a PR for this Issue?

None

Support Needs

No response