Required allowance for Function-Call Keys

[pustovalov]

Hi,

After this PR:

#330

allowance attribute became required, but the documentation states that this attribute is optional:

https://docs.near.org/concepts/protocol/access-keys#function-call-keys

allowance (Optional): The amount of NEAR allowed to be spent on gas. If omitted, the key can consume unlimited as gas

Which implementation is correct?

[frol]

@pustovalov good catch. We had an internal discussion and thought that nobody would actually need that unlimited allowance any time soon. @FroVolod will jump on it now to introduce proper parsing of “--allowance unlimited”, cause absent CLI option is ambiguous