Lack of the arguments' correctness checks

[olga24912]

In depositToNear we take the nearRecipientAccountId as string: https://github.com/aurora-is-near/eth-connector/blob/master/eth-custodian/contracts/EthCustodian.sol#L87

In depositToEVM we take the ethRecipientOnNear as string: https://github.com/aurora-is-near/eth-connector/blob/master/eth-custodian/contracts/EthCustodian.sol#L56

And we don't perform any checks for these arguments. It will be nice to have some basic one:

• nearRecipientAccountId doesn't contain :
• ethRecipientOnNear is 40/42 length long and contain only allowed symbols.

If I understand correctly, if there is an error in the address, Eth will be blocked forever.