KeyStore: Verbose error reporting

Report KeyStore/KeyMint error messages via public API.

This lets developers find out:
* Whether an error is transient or not.
* Whether a failure is due to a system error
(system configuration/state/capabilities), or a key-related error.
* Whether user authentication is required to use the key.

Test: atest CtsKeystorePerformanceTestCases CtsKeystoreTestCases
Bug: 197890905
Change-Id: I776d9e9cc01a9dc3542a63000ee0709847760963