Add clone method to ContextWithHandlerCfg

[CorrM]

Add clone method to ContextWithHandlerCfg.

Pullrequest created for: #1126

So instead of

let cfg = ContextWithHandlerCfg::new(self.ctx_with_handler.context.clone(), self.ctx_with_handler.cfg.clone());
Evm::builder().with_context_with_handler_cfg(cfg).build();

Now:

Evm::builder().with_context_with_handler_cfg(self.ctx_with_handler.clone()).build();