fix: stop the diagnostic logger from throwing while logging

[bitsandfoxes]

The bug

A diagnostic logger must never take its caller down with it. I.e. when logging from inside a catch that has already handled the failure. Throwing inside the catch because logging? You're in for a bad time.

UnityLogger.Log interpolated the exception directly:

_logger.Log(GetUnityLogType(logLevel), LogTag, $"({logLevel}) {Format(message, args)} {exception}");

So anything that threw while being stringified escaped from within the handler.

The fix

Format the message and render the exception defensively, and never let the write to Unity's logger propagate. The exception falls back to type and message when the stack trace cannot be read, so the error stays legible instead of disappearing.

Example:

Sentry: (Error) Failed to resolve hardware installation ID.
  System.TypeInitializationException: The type initializer for
  'System.Net.NetworkInformation.SystemNetworkInterface' threw an exception.
  (stack trace unavailable: TypeInitializationException)
Sentry: (Debug) Registering integration: 'UnityLogHandlerIntegration'.
...