iOS - isAvailable function generalize the error code, however authenticate function have proper error code mapping

### Bug report

## Description

For iOS application, I am calling isAvailable function when touchID is locked because of multiple invalid attempts.
My expectation was that the application will return error code:
case BIOMETRIC_LOCKED_OUT = -111

However it retuned:
case BIOMETRIC_UNKNOWN_ERROR = -100

## Environment

* Plugin version
2.2.2

Platform:
iOS
