wifi: Rename failure_reason_util to wifi_status_util

The HIDL interface now returns a |WifiStatus| instance to indicate the
status of any operation. This is replacing the existing asynchronous
delivery of success or failure (using |FailureReason| instance).

Rename the existing util class to |wifi_status_util| and add a couple of
methods to create a |WifiStatus| instance with empty description.

Bug: 32056230
Test: Compiles
Change-Id: I8488f7cd7d6ad6bd7a0c3c82a7ef83299d877d45