Also move the accounts interface to iOVM/predeploys (#1087)

* refactor[contracts]: move account interface to predeploy folder

* chore: add changeset

.changeset/hungry-pears-vanish.md

+---
+'@eth-optimism/contracts': patch
+---
+
+ECDSA account interface contract moved to predeploys dir

packages/contracts/contracts/optimistic-ethereum/OVM/predeploys/OVM_ECDSAContractAccount.sol

@@ -3,7 +3,7 @@ pragma solidity >0.5.0 <0.8.0;
 pragma experimental ABIEncoderV2;
 
 /* Interface Imports */
-import { iOVM_ECDSAContractAccount } from "../../iOVM/accounts/iOVM_ECDSAContractAccount.sol";
+import { iOVM_ECDSAContractAccount } from "../../iOVM/predeploys/iOVM_ECDSAContractAccount.sol";
 
 /* Library Imports */
 import { Lib_EIP155Tx } from "../../libraries/codec/Lib_EIP155Tx.sol";

packages/contracts/contracts/optimistic-ethereum/OVM/predeploys/OVM_SequencerEntrypoint.sol

@@ -5,7 +5,7 @@ pragma experimental ABIEncoderV2;
 /* Library Imports */
 import { Lib_EIP155Tx } from "../../libraries/codec/Lib_EIP155Tx.sol";
 import { Lib_ExecutionManagerWrapper } from "../../libraries/wrappers/Lib_ExecutionManagerWrapper.sol";
-import { iOVM_ECDSAContractAccount } from "../../iOVM/accounts/iOVM_ECDSAContractAccount.sol";
+import { iOVM_ECDSAContractAccount } from "../../iOVM/predeploys/iOVM_ECDSAContractAccount.sol";
 
 /**
  * @title OVM_SequencerEntrypoint