fix: HandlerException ingored

[roma-frolov]

Description

In the current version of FastStream, if I raise AckMessage (or any HandlerException) when processing a message, then the following line will be added to the error metric:

faststream_received_processed_messages_exceptions_total{app_name="faststream",broker="rabbitmq",exception_type="AckMessage",handler="default.queue"} 1.0

It shouldn't be like this, because HandlerExceptions are not user-defined exceptions and should not increase the error metric when they are thrown

Type of change

• [x] Bug fix (a non-breaking change that resolves an issue)

Checklist

• [x] My code adheres to the style guidelines of this project (scripts/lint.sh shows no errors)
• [x] I have conducted a self-review of my own code
• [x] I have made the necessary changes to the documentation
• [x] My changes do not generate any new warnings
• [x] I have added tests to validate the effectiveness of my fix or the functionality of my new feature
• [x] Both new and existing unit tests pass successfully on my local environment by running scripts/test-cov.sh
• [x] I have ensured that static analysis tests are passing by running scripts/static-analysis.sh
• [x] I have included code examples to illustrate the modifications