Correct exception message upon throwal

[stijnmoreels]

Describe the bug
When the secret provider or correlation accessor is missing, the wrong kind of exception message is shown when trying to register an EventGrid publisher.

To Reproduce
Steps to reproduce the behavior:

• Register the EventGrid publisher with one of our new extension overloads without either a secret store or correlation registration.
• Look at the invalid operation exception message.

Expected behavior
Correct exception message should be shown.

Additional context
Add any other context about the problem here.

• 3.3.0-preview-1