Ensure correct webhook behavior on correlation failures

[chillleader]

What should we do?

• Define how the webhook connector should behave in case of activation condition mismatch and other errors
• Decide whether we need to make this behavior configurable using the acknowledgement config options
• Make sure the webhook behavior is aligned with our expectations

Why should we do it?

To ensure no surprises for our users, the webhook connector should handle errors in a predictable manner.

This is part of the following epic: https://github.com/camunda/product-hub/issues/2157

[chillleader]

As discussed with the team, we should:

• "Flip" the switch to ensure backward compatibility (i.e. messages are acknowledged by default if they don't match the activation condition).
• Enable this feature for the webhook connector