Stop overwriting NotAllowError message when identifying errors in the browser

[MasterKale]

Twice now my error identification logic has overwritten a NotAllowedError message with one that is spec-accurate but completely obfuscates the real issue that becomes obvious if one could read it:

• A NotAllowedError reporting "Operation failed" from a Conditional UI call due to an iOS Safari bug
  • iOS Safari fails on conditional UI on page refresh #350 (comment)
• A NotAllowedError reporting a Chrome-specific block on WebAuthn due to an invalid TLS connection
  • NotAllowedError during registration #351 (reply in thread)

In both instances I overwrote these messages with "User clicked cancel, or the authentication ceremony timed out" because it was the second of two possible reasons the error would be raised. Clearly platforms are using this error type to report platform-specific errors, though, and so I should stop overwriting these messages to make it easier for RP's to diagnose issues that aren't library-specific.

[MasterKale]

This is now available in @simplewebauthn/[email protected]