General additional checks

There are a few additional checks that we recommend adding in the contract:

1. The msg.sender for the functions initForSmartAccount, transferOwnership, addOwner, and removeOwner is a smart account and therefore a smart contract. Currently, anyone (EOA or smart contract) can call these functions, but as the expected caller is a smart contract, the function should check if the value of _isSmartContract(msg.sender) is true. Currently, this missing check does not cause any security issues.

2. The length of eoaOwners.length should be checked and reverted if it is zero. Otherwise, the function initForSmartAccount could be called again.

These issues have been acknowledged by Biconomy, and a fix for issue 2 was implemented in commit