Fix proxy cov issue #167 (#186)

Fix #167


1. For non-proxy contract, the results are the same as before and in line with expectations.

2. For proxy contract, 
2.1 It is consistent with the above when running its own instructions.
2.2 while running the instructions of impl contract, relevant coverage data will be included in the implementation contract.

src/evm/middlewares/coverage.rs

@@ -286,7 +286,7 @@ impl<I, VS, S> Middleware<VS, I, S> for Coverage
         if IN_DEPLOY || !EVAL_COVERAGE {
             return;
         }
-        let address = interp.contract.address;
+        let address = interp.contract.code_address;
         let pc = interp.program_counter();
         self.pc_coverage.entry(address).or_default().insert(pc);