Refactor the import macro for foreign language contract integration

[clearloop]

the import! macro located in /crates/zink/abi/abi_macro, is currently written for tests, based on the logic of parsing ABI into rust signatures, we'd introduce the interface of foreign language integration with it

// struct Foo(Address);
import!("Foo", "../foo.json")

// we haven't had this interface yet but let's assume we have
struct MyContract {
  foo: Foo, // this is the address of Foo 
};

impl MyContract {
   fn get_bar(&self) -> i32 {
      // run contract call
      //
      // evm::contract_all(
      //   address: foo.address, 
      //    method: "bar", 
      //    args: []
      // );
      self.foo.bar()
   }
}

contracts with this macro would be pretty like the -sys crates in rust, we can simply wrap some ABIs and make them a zink library, for example, we can wrap the whole openzepplin libraries for zink contracts to use, and as a result, for calling these libraries, we can keep our interface, like

use foo_zsys::Foo;

struct MyContract {
  foo: Foo,
}

// ...

which would be the same calling a contract written in zink!