[FEATURE] 💥 Throw specific exception when factory fails without fail-safe

[jodydonetti]

Problem

Since v1.3.0 it's possible to trigger a factory fail without throwing an exception, so that fail-safe can kick in and do its thing.

But what happens if fail-safe is not enabled or if there's no stale value to fall back to?

Previously a plan Exception was being thrown, but that is hardly a best practice: we can do better.

Solution

Now a more specific exception type has been created and will be thrown, namely FusionCacheFactoryException.