Pass "error" to the callback along with "error_description"

[tushargupta51]

Currently, we only pass back the "error_description" parameter to acquireToken callback. We need to pass "error" parameter also as developers should rely on "error" property in their code instead of "error_description".

We do save the error in storage which can be accessed by developer. Though, it is not a good solution, developers can use this to get to the "error" property until we fix this behavior in adal js.